Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)
 Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

Protect your investment in diesel power and confidently extend drain intervals with our top-grade synthetic diesel oil. AMSOIL Signature Series Max-Duty Synthetic Diesel Oil delivers 6X better wear protection than required by the Detroit Diesel DD13 Scuffing Test for Specification DFS 93K222. Advanced synthetic technology provides excellent viscosity control and outstanding extreme-temperature performance, while minimizing oil consumption. The result: protection that's boosted to the max.

Package sizes include:

1-Quart Bottle
1-Gallon Bottle
2.5-Gallon Bottle
30-Gallon Drum
55-Gallon Drum
275-Gallon Tote

Product Code: DME • Brand: AMSOIL




MSDS Data Sheet

Product Details Tech Data Reviews & RatingRelated Videos

Product Applications
Use in diesel engines and, where appropriate, gasoline engines requiring any of the following specifications:

Product Application Specs

• API CK-4/SN, CJ-4, CI-4+, CF
• Volvo VDS4.5, VDS4, VDS3
• Mack EOS-4.5, EO-O
• Renault RLD-4, RLD-3
• Cummins CES20086, CES20081
• Caterpillar ECF-2, ECF-3, ECF-1-a
• DDC 93K218, 93K215, 93K214
• DFS 93K222
• ACEA E9, E7
• MB 228.31
• MAN 3575
• MTU Type 2.1, II, I
• JASO DH-2
• Deutz DQC III-10LA
• Scania LA-2
• Chrysler MS 10902
• Ford WSS-M2C171-F1

Product Description
Maximum Engine Protection - Wear on rings and cylinder liners leads to increased oil consumption and loss of compression, resulting in reduced horsepower and fuel economy. Independent testing shows AMSOIL Signature Series Max-Duty delivers 6X more wear protection than required by the Detroit Diesel DD13 Scuffing Test for Specification DFS 93K222, delivering the security of providing your diesel the extra protection it deserves.

Viscosity Control
Using top-tier synthetic base oils, AMSOIL Signature Series Max-Duty is naturally resistant to oxidation and the thickening effects of soot contamination. That, along with boosted detergent/dispersant additives, keeps soot particles suspended independently, helping prevent the formation of larger, wear-causing particles. Viscosity increase is minimized and soot-related wear is controlled. Lower volatility also helps Signature Series Max-Duty retain its viscosity after high-temperature service for maximum engine protection and efficiency.

Excels in Extreme Temperatures
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil resists thermal (heat) breakdown better than conventional and competing synthetic diesel oils. Unlike conventional oils, Signature Series contains no wax, staying fluid in sub-zero temperatures for easier starting, improved oil flow and reduced wear. Signature Series 0W-40 (DZF) has a broad viscosity range that offers 4X better cold-cranking ability than a 15W-40, making it excellent for use in both hot-operating engines and cold-weather starting extremes.

diesel oil Scuffing Test

Minimizes Oil Consumption
AMSOIL Signature Series Max-Duty has a low rate of volatility (burn-off), reducing oil consumption during operation and passing less oil vapor into the combustion chamber. It provides up to 76 percent less oil consumption than required by the API CK-4 standard in the Caterpillar-1N oil consumption test.

diesel Oil Consumption

COMPATIBILITY
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil is compatible with other conventional and synthetic engine oils. Mixing AMSOIL diesel oils with other oils, however, will shorten the oil's life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.

Aftermarket oil additives are not recommended for use with AMSOIL synthetic diesel oils.

diesel oil OfficialOil icon

SERVICE LIFE
Diesel Engine Service Life

Heavy-Duty On-/Off-Road: Three times (3X) OEM1 recommendation, not to exceed 60,000 miles/600 hours or one year, whichever comes first.

Turbodiesel Pickup: Two times (2X) OEM1 recommendation, not to exceed 25,000 miles or one year, whichever comes first.

Gasoline Engine Service Life
Two times (2X) OEM1 recommendation, not to exceed 15,000 miles or one year, whichever comes first.

Drain intervals may be extended further with oil analysis.

Refer to your owner's manual for OEM drain interval recommendations and guidelines for severe and normal service.

Note: Extended drain intervals are not recommended for performance-modified engines, when using biofuels containing more than 10 percent ethanol or 15 percent biodiesel (B15) or for 2007-2009 Caterpillar* C13 and C15 on-highway engines. Extend drain intervals beyond OEM recommendations in these instances only with oil analysis. Note: 2007-2010 Dodge**, Ford** and GM** turbodiesel pickups are also not recommended for extended drain intervals when using DHD.

HEALTH & SAFETY
This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS).

Click here to view the MSDS Data Sheet for AMSOIL DME.

Keep out of the reach of children. Don't pollute. Return used oil to collection centers.

TYPICAL TECHNICAL PROPERTIES
AMSOIL Signature Series Max-Duty Synthetic Diesel Oil (DME)
Kinematic Viscosity @ 100°C, cSt (ASTM D-445)15.6
Kinematic Viscosity @ 40°C, cSt (ASTM D-445)112.4
Viscosity Index (ASTM D-2270)147
CCS Viscosity @ -20°C, cP (ASTM D-5293)4134
Pour Point °C (°F) (ASTM D-97)-40 (-40)
NOACK Volatility, % weight loss (g/100g) (ASTM D5800)5.1
Total Base Number (ASTM D2896)10.1
High-Temperature/High-Shear Viscosity, cP (ASTM D5481)4.5
Sulfated Ash Content, wt. % 1.0

6x More Wear Protection than Required!

Understanding the 2017 FA4 and CK4 Diesel Oil Specifications

Diesel Power Challenge

Did this product meet your expectations?

(click on a star to rate)
Product Name: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)
Current Rating: 4.92 out of 5 stars
Total Votes: 284 vote(s)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Pete: space

AMSOIL

I have tried every kind of synthetic for a diesel engine and found AMSOIL to be the best by far. I have a E350 Ford van with a 7.3 power stroke engine. I have gained two miles per gallon and the motor runs smooth.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Kevin: space

my Cummins is loving it's new life blood

First 10K was great, pushing this last oil change to 25K will update review after my oil analysis is done.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Don M: space

Great Products

Primary use is for my Cummins 6.7 in my 2014 Dodge Ram. We use the truck for towing and I feel that Amsoil Signature series helps protect my truck in severe duty towing.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Austin the concrete pumper: space

Makes my engines happy, and me happier

Well, the reality is... Diesel maintenance is expensive, no two ways about it.

With this oil I can run longer intervals with less deterioration and degradation, even on the heui engines I own and maintain (which works oil to the max)

I have to say, with the oil analysis that I get back consistently telling me that my engines are happy to run extended change intervals ((while still changing filters at normal intervals)) I'm a happy camper, over the next ten years I'll save tons of money.. tell me that wouldnt make you happy.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Casey: space

Best Diesel Oil!

I use this product in my Ford F250 6.0L PSD. I noticed my turbo spooling up easier and quicker after switching from conventional oil. The 6.0L PSD's are very tough on the oil due to the high shearing of the oil pressure run fuel system and the lubrication of a hot turbo. Many professionals highly recommend changing at 6000 miles in the 6.0 PSD. I run my diesel kind of hard with pulling a lot of heavy loads and running a hot tune for daily driving and playing around, my last oil change was at 9000 miles. Oil was still full without adding any, still feels more slippery than new conventional. I reuse it in old oil burning engines and it cuts the oil consumption in half. A relative of mine has been using my drained Amsoil in their beater car for over a year and it cut way down on the oil consumption. I would run the oil longer in my 6.0, but like to recycle it into the older engines. I use only the Amsoil long life oil filter. I may purchase the oil test kit in the future just to see if there is any depletion in the strength of the oil, but I am very happy with my use of this product.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ryan: space

I'm hooked! Easy though as it's a quality product!!

So glad I've switched to Amsoil products! I want nothing but the best going in to my engines. Outlasts any lubricant I've ever used in my vehicles.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by AA RON: space

GREAT PRODUCT

Amsoil synthetic keeps my work truck running and me making money. The only way to go.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by MR G: space

Great product

My cummins runs so much smoother

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by None: space

I would buy this oil exclusively

Best oil made

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Robin: space

Yes

I trust this product compact to what we getting out there it is proven to have the correct antiwear detergents blend into the oil and you can listen to the effectiveness and quieter motor when idle and driving at your cruse speed

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by SD: space

Great oil

I use this on my 2018, Super Duty 250

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Hawk: space

Awesome product!

The best oil product I've ever used.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by STW: space

GOOD STUFF

GOOD STUFF

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Matt the Hunter: space

I will keep using this product

I use this in my Daily Diesel Truck,I love the power it frees up.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bigb: space

#1

200k on my cummins diesel with amsoil.still like new.great stuff.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jr: space

Great oil

Use this oil on 17 duramax works great glad i can get quality oil shipped to my door gives me peace of mind my truck has the protection it needs to do its job

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ink: space

I use this product in five vehicles

Upon purchase of a new Toyota the service rep recommended Amsoil. I use Amsoil in a 2014 Tundra, a John Deere 748 Diesel, a 2017 Camry, a 2014 Outback, a 2016 Highlander, and a Honda lawnmower. Well satisfied at this time.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by J-Rod: space

The best

This diesel oil is the best stuff out there! I use everything AMSOIL!

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by MB: space

great product @ great price

Amsoil products fit the bill for almost any application @ a affordable price.
There products are vastly superior to most on shelf products, They even make
specific products for specific needs. all this with great tech support and easy online
purchasing. I will continue using Amsoil products for these reasons.
Thank you Amsoil.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Eddie: space

Great product

Great stuff. I've been running this stuff for years. About 15,000 miles per change. I know several people that have ran it the full 25,000 miles.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Perez: space

First time user

I have an 05 6.6 duramax and like that this oil gives me more miles between oil changes.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Gus: space

Good oil

So far so good, like to put 15w 40 synthetic on my Cummins. Lets see next oil analisis how's holding up.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mike: space

Great products

I've been using Amsoil in my 04 Ram 5.9 L Cummins almost since it was new. 280,000 miles and no engine problems at all!
Love it!

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jarvis: space

Great product

Solid premium product. I try to take care of my vehicles the same way I do my body. I look for the full protection of the lubrication this product provides in the rigorous operations I put my truck through, and the many miles I do. I'm happy with it.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Steve the boss: space

Yep. Have always used Amsoil. It's the best

Have used the diesel oil in my Ram from Day one. I believe it's the best on the market. I trust it.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Chad: space

Good stuff

Changed all the fluids in my 99 Superduty(220000 miles) over to Amsoil products. Truck starts easier in cold weather trans temps have dropped 10-15 degrees towing and I gained 2 MPG.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Wild Bill: space

Will be buying this product again

Used in my 2014 Ram 1500 Eco Diesel

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Pdnh: space

Great

Was using Mobil Delvac 1. Would change oil at 15000 miles, changing the filter at 7500. Doing oil analysis at 15000 miles the oil was at 70%. Switching to Amsoil I change at 25000 changing the filter at 12500 the oil is just a little over 80%. Results speak for themselves.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Justo: space

I would buy this product again again

I am using the amsoil for the last five years
About 100,000 and 120,000 miles per years
My semi truck and me we are happy and saving money it's amazing for the best

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jemeda11: space

I would buy this again and again

In my diesel trucks. Awesome oil. Lasts 25000km before I even think of changing it.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Vegadriver: space

Great oil

Run this oil in my 2012 Duramax. Can go a full year without oil change. Saves me money. Also use the Amsoil filter.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by JasonV: space

EcoDiesel oil for my truck

Love it.
Good quality oil for a good price for this quality oil.
Will Definitely buy again as its cheaper to do it my self than having the dealer do it and I get a way better oil for my truck.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by NYMustang50: space

Great Product

Stuff is worth every penny. Oil analysis test prove it. Always use Amsoil in all my personal engines.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by PAPPY: space

BEEN USING IN MY 2007 GMC

ALSO IN MY SS2 CAMARO

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by DWS: space

All I use

Been using Amsoil diesel oil and Ea08 filters every 15k since the truck turned 30k miles. Have 276k now.
Could do a longer interval with testing

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ron: space

Max Duty 15w-40 Diesel Oil = Good Stuff

I am relatively new to Amsoil but have and have both Duramax and Cummins - currently have a L5P Duramax with an Amsoil Duel Bypass oil filter set up which I did not have on my previous Duramax. Thus, apples to apples may not be in the following:

1. Blackstone reports come back much better than with the Rotella T-6 I was using in the prior '15 Duramax actually with about 7500 vs 5000 miles.
I got some usage w/Rotella T6.

2. A bit of oil usage with the Rotella t-6 but absolutely none with the Amsoil.

Repeat not apples to apples exactly as different engines and the L%P has a duel bypass set up on it.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by BRIANS cummins: space

AMZING STUFF 429,000 miles

I use the 5w40 and 15w40 in my 2003 Dodge Ram 2500 5.9 cummins ... when I got the truck it had 378,000 also had little blow-by.. it ran mobile 1 most of its life .. switched to AMSOIL signature series (max-duty) and the blow-by was gone and it also slowed down completely with drinking some oil .. 7-10,000 and I might need to add 1/2 qt this stuff is AWESOME .. now I have 429,000 and this cummins runs like its NEW with 10,000 miles on it .. everyone that I know with a cummins , I get them hocked on it also .. everything I own has AMSOIL

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mark: space

I've used Amsoil for over 20 yrs.

I've used Amsoil in my last 5 class 8 trucks. Absolutely no problems. Why on Earth change. Use Sig. 5w-30 in my Ecoboost too

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Reg Moody: space

I use Amsoil exclusively

Used in all my vehicles for years

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mike: space

Diy

Maintenance

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dogman: space

I have used Amsoil products for years and will continue to.

I use this oil in my '02 2500 Ram Diesel to protect that engine for the long haul. The 5.9L Cummins is the last of the "loud ones" for Dodge. I want to try for 750,000 to 1 million miles before it needs any real work put into it. That sound is one of the reasons that I bought it in the first placeI love how it runs and I get great longevity out of the oil. If you run a diesel you would be crazy to not try some in yours. Worth every penny!

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by rdj519: space

2010 gmc Diesel truck

I installed the bypass oil filter system when I bought it new. Oil sample every 7000 miles. This oil and system is the best thing I have ever done for my big truck. Only the best for my baby

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jack: space

Too Early to Tell

I have always run synthetic oil in everything, but since I bought my Duramax, I thought I'd try you product and filter. So far so good, I'll let you know in about 150000 miles.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by obg: space

oil

Great stuff wouldn't use anything else.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by REJ: space

I will buy this product again

This is the only product that I can find that is recommended for my Eco Diesel and it performs as advertised.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mike, 2017 Dodge Ecodiesel: space

Solid Amsoil User

First time have used Amsoil diesel oil. So far so good. However I didn't notice much change in fuel economy after using Amsoil 5W40 SS diesel oil for my first oil change in this truck, in town driving. High way driving did show some improvement, all the way up to 30.2 mpg, previously had gotten 29 mpg. I think part of this is my motor is still breaking in as diesels take awhile to do so. Overall I am pleased & have used Amsoil in both of our vehicles going on 18 years.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Pinkpeaches10: space

I would always buy amsoil

Perfect oil.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Doc Pat: space

I always use this product on my diesel trucks.

I use this on my 3 diesel trucks. 1985, 1994 and 2001 F 350.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by JGD: space

Outstanding product!!

I am using this in my new F250 Diesel, as always Amsoil has created a superior product you can depend on. I can physically tell a difference just by using this oil. The truck runs so much better.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jonathan: space

Awesome stuff

I am rough on my trucks farm use hauling ext... Has 300k+ doesn't lose it burn a drop still run 25k between oil changes love my amsoil

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Russell: space

The only oil

I was told it was it would help eliminate dust particles from the DEF system that build-up in an engine. It has helped with eliminate dust buildup in the engine significantly. Immediately after using the first time, many miles ago, I felt more power being produced from my engine. I'm a very satisfied customer.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Butch: space

I use Amsoil in all my vehicles.

I have used Amsoil for 20 years. I like the extended oil change intervals, it saves me money and doesn't damage my equipment. I took oil samples and had them tested after 18,000 miles. They came back no wear and more mileage before changing. This was on a 1978 Dodge van with 180,000 miles. I currently use Amsoil in my 2006 Ford F350 6.0 diesel FX4 in all gear boxes, and 2012 Ford fusion. I am very satisfied with Amsoil performance.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Joe: space

Have used Amsoil for 20 years.

I use Amsoil in every combustion engine that I own. Vehicle, farm equipment, lawn mowers welding machine and generator. Never had a lubrication issue with any of them.
Best oil on the market hands down!

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Scott: space

Synthetics

I believe in synthetics and Amsoil.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Doug: space

I will keep buying this product

love this product, but have nothing to compare it to because the last two new trucks I've purchased i change the motor oil and transmission fluid as soon as i get home. sold my 2007 GMC Classic Duramax 4X4 with 180,000 miles for over book price. To a mechanic. i could go farther but always change oil at 5,000

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jason: space

I will purchase this again and again.

I use this product in a 3/4 ton work truck.
Very high quality product.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Grandpy: space

Great

No worries

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Super04FX4: space

Best Diesel oil on the market

After trying several different synthetic diesel oils over the years...I have settle on AMSOIL as the best. I see consistently better cold starts and the extended change interval is a huge plus!

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ray: space

I use Amsoil prod in all my vehicles.

I have used Amsoil 5w- 40 since I purchased my truck 8 years and 210,000 miles ago. The truck runs as good today as it did then.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by GregM784: space

Amsoil & Cummins

Runs great, runs cooler, a product you can trust.

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tom: space

Over 25 yrs using AMSOIL...

I'm sold! I've used Amsoil products in all my vehicles for over 25 years. Engines run more quiet/smooth, better fuel mileage, and longer engine life. I recently convinced a friend to try Amsoil, they had an immediate 4-5 mph increase! What more can i say?!!

Item Reviewed: Premium Diesel Oils (DEO,DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Duramax: space

I use this in my 2017 Duramax. Love it

I have used amsoil in my 2008 and now my 2017 duramax. Love the reliability and superior quality of the oil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Copper: space

Duramax diesel Noisy lifters

Been using this product for about a year I had noisy lifters on my truck using amsiol has Quiet them where I can hear them anymore Great product

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by REC: space

Usage

I have found that using Aimsoil products I have added longevity and life to my vehicle. I drive around 1500-2000 miles per week.
Products service my vehicles mechanical parts awesome.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Zlob66: space

Will continue purchasing

Used in a 2005 GMC Sierra 2500 HD, have used Amsoil products exclusively since I purchasing the truck, will definitely continue using.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tazman: space

I use nothing but AMSOIL in all of my vehicles.

I use AMSOIL in my 2007 Dodge RAM 3500, my wife's 2013 Ford Edge, 3 Waverunners, and all of my power equipment. I have not experienced any issues with any of these applications. Warranties are not voided, and fuel mileage in both vehicles is improved compared to conventional oils.

My Dodge Ram has the Cummins 6.7 liter diesel with 268k miles. The truck is still purring like a kitten, and doesn't burn a lick of oil. I am still on the original transmission without any re-builds as of yet. (very uncommon for the Mopar trannies). I extend the oil change intervals to every 9k miles, even though the manual states not to extend. I have not witnessed much , if any fuel dilution in the oil.

My Wife's Ford Edge has a mere 78k miles on it. I change the AMSOIL Premium oil in her car every 15k miles, even though the AMSOIL reference sheets state she could go 25k. I just like being careful.

I run the marine 10W30 in the Yamaha Waverunners and have smooth acceleration, without any vibration or oil burn.

Overall, I love the AMSOIL products and would recommend to anyone looking for a top end, fully synthetic, highly protective oil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Kodiak: space

Would buy again

My Diesel runs smoother and quieter

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by McKittrick: space

Great all around product.

I never knew you could see the difference in oil. I switched to amsoil a few months ago. I noticed easier starting in sub zero weather, and a slight increase in fuel mileage. I was running a synthetic before. Amazing.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by celtic: space

Superior performance

I became aware of And oil in 1985. I knew how good synthetic oil was as my older brother was a petroleum engineer and he declared that synthetic oil would soon be the dominant motor oil. I had my brother run some tests on a quart of And oil and he reported that the stuff was off the charts. He and I became long time customers. I have never had any type of engine failure due to poor oil performance.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Rosie: space

Longevity

Installed AMSOIL in my old Chev Diesel. Changed the filter every 5000 miles . Checked quality of oil each time. At 20000 miles the oil was still good. Amen. This was at 100000 miles and used a quart every 3000 miles .mwhrn traded atb441000 miles it used only 1/2 guard in 10000 miles . Had an old 99 suburban diesel bought used. Was up to 1 quart every 4500 miles when traded at 352000 miles.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Russ: space

Great stuff

Great oil for my 2500 Jd

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bryce: space

Excellent product! Use in every diesel I own

I've used this product as well as many other amsoil products in many trucks and pieces of equipment and they are superior to any other on the market. Much smoother running with lower temps and increased mileage.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jay: space

Great Oil.

I use this oil in my dodge 2500 cummins and it works great. Lasts long.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by DR: space

I will buy this product over and over again

Better fuel mileage

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Nordy: space

Love it

Love the protection and convenience of oil changes once a year. Saves money and time.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Cujo: space

Only oil go my things!

Duramax seams to like it, oil samples great @ 10000km, filter change and re sample @ 20000km!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by sawdust: space

I buy AMSOIL

I have used AMSOIL for over 30 years great stuff!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Charlie: space

Only oil I use

Only use the truck to tow keeps oil temp down

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bill: space

Love my truck

The oil in my 199 F-250 SD with 7.3 diesel, bought new, use to get its oil changed every 3-5K miles for the first 6 oil changes. Then the switch was made to Amsoil Synthetic, with Amsoil oil filter. The oil still looks new after the first 3-4K miles and is changed every 10K miles. Although I have had no problem with this vehicle related to lubrication, the vehicle may be considered low mileage with 262,000 miles and o8il consumption has been greatly decreased. Love this oil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Greg: space

Best oil for my Duramax

I have had Silverados with Duramax for daily use and towing a travel trailer. I change the oil at extended intervals using the Amsoil and have used this oil with confidence in all seasons and conditions around the country. Signature Series is the best!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Brennon: space

Great results

Before using this product in a 2015 Silverado 2500 I had consumption of standard oil. Truck was using 1 quart of oil per 5000 miles. After switching to this product I have not experienced any consumption.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Smitty: space

Run it all the time

I have used this since the truck was new. 110,000 miles and it is running like new.

During the recent cold weather, it started right away and oil pressure was At recommended level. Great protection!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mike: space

Great product!

2000 F250 7.3L TURBO!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Sixpack: space

15W-40 Signature Series Max- Duty Synthetic Desiel Oil

Engine oil, Quality

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Chief: space

200,000 + miles

I bought a 2001 F250 with 70,000 miles on it. After a couple of trips to a local quick oil change every 5000 miles at a cost of 150.00 I decided to try Amsoil diesel oil and am very glad I did .I use Amsoil diesel oil and filter I have extended the oil changes to yearly this by itself is a substantial cost savings the truck runs great and averages 16 mpg. It now has almost 250,000 miles on it and counting

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Clark: space

Get It!

This oil is all that it says it is.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Andy Frame: space

Excellent protection at a reasonable price

The only oil I trust for my twin turbo Duramax

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bob: space

Excellent motor oil products

I've been using Amsoil motor oil in my 2007 Ford F350 diesel now for past 9 years. Each time I change the oil, which is every 5000 to 6000 miles, I also take an oil sample for lab analysis. The lab reports have always good. No appreciable wear, and it's viscosity after 6000 miles is well within acceptable ranges. Internal parts of the engine remain extremely clean, no deposits or sludge buildup.
I also use Amsoil XL motor oil in my 2016 Subaru Outback, and before that, a 2010 Forester and never had any engine problems.
I am extremely sattisfied with all their products, from engine oils to gear lubes, which I have been using in my F350 for 9 years.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Armory racing products: space

I would recommend this to anyone with a diesel

This oil quietnes down all Diesel engines and last long with no signs of thermal breakdwn

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Rosco: space

If you like the best, then this is the stuff.

I use this oil in my 7.3 and never have a problem with cold starts even with the truck having 200K. Truck runs great with this oil and I have lower oil temps and smoother idle.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Gee: space

I use AMSOIL in everything I own.

I use AMSOIL in everything I own.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Teddy: space

Best oil ever

Amsoil is the best oil products out there. I run heavy loads with my truck and travel a lot. I get great mileage out this oil and it holds up to the extreme temperatures here.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by noname: space

I continue to use this great product

I use this in a 2000 7.3 Ford Diesel. Motor has over 200,000 miles and still runs like a top. I will continue using Amsoil products; my engines run great and stand up very well with their products.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Wumba: space

Great Product!

Been using this in my diesel truck for years with never a problem. Online ordering was quick and easy!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Randy: space

Diesel oil

This is my second Duramax and AMSOIL is all I use in all my vehicles.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Scott: space

Great so far

used in a 6.0 Powerstroke. Probably the most demanding motor of oil because of the design of the 6.0 Powerstroke and the use of the oil to hydraulicly power the injectors.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by MtnDsrtMn: space

Best dang oil out there!

My truck just keeps running smoothly. I TRUST Amsoil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ryan: space

Worst oil for L5P Duramax

I had this oil in my L5P Diuramax for 5,000 miles. I have never heard such a loud clicking noise come from this motors till I put this oil in. Will never use again. Oil consumption went from zero to adding a half quart every 1500 miles with this oil. Could not wait to get it out of my engine.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Cptn_Jon: space

I LIKE THIS OIL

I bought a new GMC 3500 Duramax in 2005. The first OIL change was AMSOIL Max Duty Diesel pool 15W-40. With this OIL I only need to change OIL once a year (AMSOIL recommends once every 20000 miles) and I only have 10k per year. The OIL is costly but with the perfered fostered card ($20.00 per year) you save in the long run.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Lance: space

Great product

Very affordable and an excellent product!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by 1: space

I will buy again

Great

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jr: space

Awesome products

Use Amsoil in all my vehicles and toys.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by WIll the pill: space

Great product

I will continue to use this product.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by DarwinG: space

Great products

Always been a fan.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by The Butcher: space

Best oil around

Love amsoil! Ships right to my door and is always quick to arrive. It's all that's been run in my Cummins since it had 60,000. I am at 280,000 and counting. Amsoil speaks for itself!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mr. Stevens: space

Super product

I've been using this oil for 25years . Would never stop.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Agent: space

I would buy this product again

Engine

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Spike: space

This product is great.

Since using Signature Series Amsoil in my F350 7.3 my truck is quieter and my mileage has increased. This oil is a miracle, I've been working on vehicles for over 40 years and this product has given me the best results of any lubricant ever.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bill: space

7.3L Diesel vs cold weather

In addition to long interval oil changes my oil has to get me through all four seasons especially the cold North Eastern winters. I've tried many brands of oil and Amsoil Signature Series has proven to be the best. Cold starts no longer an issue if I forget to plug in my truck overnight or just leave it off for a shift at work. I really like this oil and trust Amsoil products.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bob the Old Engineer: space

Only Use AMSOIL Products

Used the diesel oil in my bosses 2004 Chevy 3/4 ton 2500 PU,After this demo,will use in all equipment

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dieseldad: space

Still looking at results

Diesel motorhome and 2004 Ford PSD.
1998 Jeep Wrangler and 2015 Jeep Cherokee.
All lubes in all my cars are Amsoil.
I will use nothing else.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Terry: space

I will continue to use each time

Great product, will use each time I change oil

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Duramax: space

Yeah

This is the best oil I have ever used this oil makes every other oil look like valve grinding compound

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tattooedguy: space

Great product and pricing

Amsoil is a great product, great service, I use there products in my 2016 dodge diesel

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dusty: space

Amsoil Synthetic Diesel Engine Oil

Best diesel oil on the market. Wouldn't be caught using anything else. Read the specs.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Willie: space

Repeat customer

I've used this oil for a while now and all I can say is I love it. My truck runs smoother and doesn't burn oil when I'm pulling.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Blake: space

I purchase this oil for every chance

I purchase this oil for the soot contamination, fuel economy gains and the wear additive package. I can tell my Duramax doesn't "tick" anymore and the fuel economy is much better. I can also go longer between changes. All in all a great product.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ski: space

Deisel 15w40

At first the motor was running smooth. I was excited and thought I had the best oil on the market. A couple if months later I can see the final results. Amsoil is good as like the rest of syn. Oil is. For deisels they need to make a thicker oil for Arizona then they will profected it. Im asking them to provide the research because I believe they could be the best.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Denali 16: space

One of the best products for a diesel on the market

Can't be more happy with the oil I've been running it for almost 10 years your missing out on the quality of this oil if your not using it

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Nate: space

Great product!

Engine runs quiter and seem to get better fuel mileage. Very happy with the oil product.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Chris: space

Diesel oil

I like this oil in my 99 ford power stroke. Holds up well.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mr.AH: space

Will always use this oil

Use this oil in a tow vehicle never loses a drop of oil in 5000 miles

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Adam: space

Hands down the best oil

I run this stuff in my Duramax and have since I bought it in 12'. It holds up to whatever I put the truck through. Best bang for the buck on the market.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Gerald Barber: space

Amsoil

Although I've never use this oil before I'm confident I'll love it as I've been useing it in my M/c for years ! You just can't go wrong with amsoil!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Rosco: space

Switch conventional oil to Synthetic oil

Being a new customer to Amsoil, I've read lots of reviews and spoke with Amsoil Tech several times, and lots of satisfied customers before making the switch. I'm still a few thousand miles away before the first oil change. This is with Amsoil oil filter. With all the above sad, I'm very satisfied with the product and the technicians.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Loren from pa: space

Very high quality

Have a 1996 3500 5 speed and have used amsoil in everything since it has had 15,000 and it now has 358,000 with no major breakdown

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by No: space

Yes

It kept the engine cool. It doesn't break down.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Greentown Joe: space

Great product

My mileage increased a bit. The engine runs a lot smother. I plan on keeping my truck for many years and this oil is go to oil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Highheat71: space

Nothing Else For My Cummibs

Best lube oil for my one ton Ram 3500. But not without the Amsoil EA filter.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Cliff: space

I would buy this product for any vehicle I have.

I use 15 40 in any vehicle I have which includes my tractors, lawn mowers.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dolly: space

I will continue using this product

I drive a lot of miles in a short period of time and I don't have time to change oil every 5 to 6ooo miles

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Hotshot John: space

Won't buy anything else

I completely switched my Dodge Ramsey 3500 to Amsoil at 140000 miles. Started out doing complete oil changes every 20k with just filter at 10k mark. Decided to have an oil analysis done. By time I have next sample tested it will be at 30k miles on this oil change. Saves money and downtime.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tk: space

never buying anything but amsoil

Perfect product

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Studentofbudo: space

Excellent product

This is an exceptional oil. Definitely made my ol' 6.5 detroit run smoother and helped with mileage!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Yelly: space

Best oil

For my Duramax diesel

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jerry: space

this product is the only one I use

We have three dodge diesels and two gas vehicles and its the only product I use, Some fuel filters they don't have and I use Wix for that. they don't make a fuel filter for my Cummins motors or I would use them for them.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Teddybear: space

Rock solid performance

You can't go wrong with the best of oil produced on the planet
Peace of mind means everything and Amsoil gives you that peace of mind

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ron: space

Love the new diesel oil !!

Use this in my 2015 super duty 1 ton dully.
A do a lot of heavy towing long distances

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Gmc 2500 Diesel die hard.: space

I would buy again

I use the product due to the turbo in the Diesel engine. I want to run the best that can withstand the heat produce by the turbo

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by CLYDESDALE: space

Simply the BEST better than all the rest ! ! !

I have a 2011 Chevy one ton dually long bed . Now over 100,000 miles and is running great I feel because I have used Amsoil since day one . I have used every brand with prior vehicles and always go back to Amsoil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bobcat1: space

Love your products!

Buy diesel, gas oil plus PI for my gas vehicles. Amsoils is the best!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by RRDan: space

Repeat purchase

Been using Amsoil HD Diesel oil for many years in Ford Turbo SDuty. Best oil out there!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Whale pilot: space

I only use Amsoil

I'm running the 15w-40 Amsoil Signature Diesel in my Corvair air cooled engine in my 22 foot RV. Very heavy duty use for a 3 liter engine from the '60's, and it performs perfectly, along with the Amsoil 75w90 Severe Gear in my differential, and Amsoil ATF in my Powerglide transmission. I use nothing but Amsoil products in my 17 Prius, the 16 Subaru Forester Turbo, And every car I have owned in the last 15 years, and will continue to do so.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Danny Boy: space

I only use Amsoil products.

I like to take extra care of cars that I love. For those cars, I only use Amsoil products. Why? I trust and appreciate the information and research they provide. I'll pay extra for that trust.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dark Cloud: space

Great stuff

Best oil out there. Installed a bypass filter system as well. Very happy with all aspects. Installation was simple

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by El viejito: space

Better oil

I got two diesels trucks and I bean use this products for few years I like how keep my trucks running great

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Moongypsy: space

Excellent, improve performance in all areas, millage, temp,

Yearly oil changes, how good is that!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Adam: space

Synthetic Diesel Oil

Used for oil change in 2005 Chevy Duramax diesel, have been using AMSOIL for years now, great for extended oil change intervals have no complaints about product thus far.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dave: space

Only Oil going in my truck!!!!

I have been using Amsoil for many years. Amsoil is the only product I put in my machines! If you don't have time or inclination to change your own oil, buy and take it to whoever does your oil changes you will still safe money and your vehicle will love you.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bill: space

Great Product

I run this oil and only this oil. Do changes every 20,000 miles and never have to add any oil during this time.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mark: space

Great product

I'm using this in my Onan air cooled generator in my motorhome.
Has run all day in some fairly hot temperatures (mid 90s) with no oil breakdown and generator uses Very little oil between scheduled changes.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tanker Man: space

Truly amazing.

I'm using this in my diesel pick up. I can't believe how much smoother it runs. And the mileage improved so much I thought the trip computer was broken.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by BG: space

Great product

Amsoil is a great oil. I personally change oil in 8 automobiles and light trucks. Also 1 motorcycle and two lawnmowers. My highest mileage is 200250 miles. I can tell you that Amsoil and their filters will do a superior job. The only down side is the shipping charges. Amsoil is priced about the same as Mobile 1, but the charges mean you pay top dollar.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Rob: space

Protection and flexibility

I use this product for two reasons. It offers me excellent protection and performance in
my Diesel engines and because the durability is so good I have flexibility on my service
schedule. My schedule may change and the weather here in New England doesn't always cooperate
and these products let me service at my convenience.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Toad: space

Nothing but the best for my vehicles

so far so good . I believe in Amsoil . I expect the best from this oil . My vehicles depends on it ! I run this in everything I own!!!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Michael: space

Great stuff.

I use it in conjunction with the Amsoil bypass filter.
Usually Change oil after 20,000 miles or so.

It's great oil, as is your trans and differential oil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Hey_U: space

The best of the synthetic oils I have found.

I use every product I need for our truck and RV and yard equipment.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by gofastman: space

Great Product

I have used amsoil in everything i got for the past 10 years, and i cant say enough about it.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by obars: space

Hope it does well

KIt was a nerve racking decision to change to Amsoil in my Old 1993 Dodge Cummins. I really hope it holds up. So far So Good.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Issac: space

Buy again... Yes

I purchased this for a buddy he has had no complaints. The shipping speed is awesome.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Elkjr: space

I would buy this oil again

Used for my F450

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jeff_Moore3: space

Absolutley i would buy again

Just what the dr. ordered. cooler running longer running less oils changes. fantastic product

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Farmer Jeff: space

Runs well in my Ford PowerStroke and tractors

Use in my 2003 Ford 6 liter powerstroke engine and tractor
No problems with the engines and provides great value

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jason: space

Great Long Lasting Oil

I have changed all fluids to AMSOIL. The oil viscosity is superior to any on the market. I do the recommended oil change to may 2500HD Duramax. Even after a 10,000 mile oil change the lubrication in the oil is still as if it were brand new. AMSOIL is the best to run in any motor. Give it a shot you have nothing to loose with using AMSOIL products.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by BladerunnerRet.: space

Amsoil only makes outstanding products

I live in a cold climate and have never had to use engine block heaters in winter.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mikey: space

Awesome

Increase oil pressure and smoother idle.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Velcro_Ninja: space

I trust Amsoil fluids and so should you..

I really appreciate the ability to use the "My Garage" to identify the products and capacities listed for each of my vehicles. That with Amsoil's excellent write ups on their products gives me a piece of mind that I have the right fluids for each vehicle.
This oil has all the additives my old truck's diesel needs to stay running for another 250,000 miles.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Ford F-150: space

Dodge Ram 2500

great oil. last a long time with the proper bypass set up.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dodgeram: space

Dodge Ram 2500

great oil. last a long time with the proper bypass set up.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by old shop teacher: space

diesel oil for my chevy duramax

Excellent fluid, haven't used anything else for years, thanks

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by 9quad: space

Ansome

Amsoil is an ansome products.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Kevin: space

Best all around

2007 Dodge 6.7, engine never sounded smoother. Best investment I've made.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by California Buckeye: space

An oil company I rely on.....

Everything I own I use Amsoil in. 2 stroke, 4 stroke, car, truck, trailer, motorcycles... Everything!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Dabear: space

I have bought this again and again.

Diesel

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Big T: space

Best oil you can buy

I run this in my 07 duramax it extended my oil change interval from every 5000 miles to every 12000 miles and my truck runs cooler plus I picked up over a mile per gallon on fuel mileage

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Nica: space

Yes

I noticed I get a better fuel gas mileage

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by L.: space

12 years and counting

I have been running this oil for over 12 years on my F350 7.3L Diesel. Still running strong.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mitchell: space

I will continue to use Amsoil in all my vehicles.

Always quality. I run this in my 2009 Ram 6.7 Cummins. Been running nothing but Amsoil since I bought it in 2010 and no issues.
I also use Amsoil Signature 5w30 in my hotrods too. I have a 1967 Chevelle SS with Chevrolet crate 502 as well as a 2013 Camaro SS 1LE
I never worry about oil related issues with Amsoil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tom: space

5 years and counting

I have used this product in my 05 Dodge 2500 for over 5 years and hasn't let me down. Great protection and good in the could mouths with could starting

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Robert: space

New GMC Denali

Bought a new GMC Denali and I will use NO other oil it a $60K plus vehicle!

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Eldon: space

I trust Premium 15W-40 Synthetic Diesel Oil in my truck.

This is the only oil I have used in my 2008 Chevy 3500 HD truck since the first oil change. At this time it is not a high mileage truck and generally change the oil due to time limitation and not mileage. However when the truck is being used it is under somewhat severe conditions and I trust Amsoil to take care of it. I will not at this time consider any other engine lubricant for this truck.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

Reviewed by Dk: space

Winter start

Truck not plugged in -40c slow crank still started. I believe 5-40 made the difference. Good oil.
2005 dodge 2500 5.9 cummins
I would recommend this to a friend.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)
Discussion Url

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Uncle Denny: space

25000 mile oil and filter

I've been using AMS 15w-40 and the 25000mile filter for over 170,000 miles and have been completely satisfied.The fact that I don't have to take the time to get an oil change every 3000 to 5000 miles helps a guy like me who's on call 24/7.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by J: space

Great product

Using the premium synthetic oil in a 03 cummins, instantly noticed the truck idling better. Glad to extend time between oil changes as well.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by RMS: space

Great Product

I think the products are great. Been using them for a long time.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Larry: space

DODGE RAM RUNNING LIKE NEW

I began using AMSOIL 15w-40 Synthetic Diesel oil 3 years ago. I can tell a definite difference in the performance of the truck & there has been increased fuel mileage with & without towing my 5th-wheel. I also have extended the interval of oil changes to 15,000 to 18,000 miles.
Based on my positive results with this product I also had my transmission fluid changed to Amsoil.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Sam: space

Premium 15W-40 Synthetic Diesel Oil

I Can always count on great quality and fast shipments from Amsoil. I have only used there product on my 2007 GMC Diesel truck from the day I purchased it brand new.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by RVer Al: space

Amsoil Premium 15W-40 Synthetic Diesel Oil

This product ROCKS! Have used it in my diesel truck since my first oil change in 2006. My truck has 170,000 miles and still runs like a top and still pulls my 5th wheel all over the USA. Also use an Amsoil oil filter and together they are the best in my humble opinion.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Fred climbs Colorado 14 teeners: space

Synthetic Oils are by far the Best

I use The 15-40W in my 2014 Ram 3500 with a Cummins 6.7 diesel engine. I pull a cargo trailer daily for my construction business and also have a 40 foot 5th wheel trailer that I am on the road with 45 - 60 days a year. I never have to worry if the engine is being well lubricated.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mat: space

It works

I have been using amsoil in my truck form the day I got it about 5 years ago, Chevy silverado 2500hd Duramax and I have to change my injectors out at 169000 miles the inside of my engine was so clean you could have ate off it. I now have 240000 miles on the truck and drive it as a daily driver over a 100 miles a day. And still use amsoil

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bob L: space

Great product. Will be buying more in the near future

Our duramax is a daily driver along with pulling a 43 ft toy hauler. I will be purchasing other products also.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by ASAPIE: space

Great product

I have used this product for many years and I have had great results. I am glade I came across amsoil the product has saved me alot of money.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Tony: space

I will never stop using it

Duramax 6.6 runs quiet excellent feul mileage

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bruce: space

2011 Chevrolet diesel truck

Have used AMS Oil for years and it has performed as advertised. Was always a little tough to find a salesperson close to home now it is very simple to order and delivery was fast.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by killer tom: space

Oil change on a 6.7 Cummins

Did an oil change and filter and first week I notice that the engine had smoothed out , and my mileage went from 11.3 liters per 100 k down to 10.6, that's just in 22 kilometer ride to work .Can't wait for a highway run coming in September.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by ca2500: space

Not worth the cost in my opinion

Can't say I had any issue in my 2014 Duramax but for the cost I will be buying something else. I just cant stand lettingmy truck go 10k++ miles on a single oil change but that's just me.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by onetexasoldman: space

shipping

have always used Amsoil
had my order within a couple days very fast

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Jeff: space

Extended drain intervals

I operate a 2013 Ram 3500 I use Amsoil oil along with Amsoil bypass filtration for a 45000 mile oil change intervals with clean oil analysis

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Pete: space

Premium 15-40 diesel oil

Been using the oil since the vehicle had reached 25000 miles. Now it has just short of 120,000 miles. The oil lasts one year. I notice no oil comsumsion between oil changes. Use the truck to pull trailers beside just normal driving. Also belive that the oil aids in cold starts during the winter months. Starting in sub zero weather has not been an issue as todate.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Mac: space

Excellent Product

I switched from the standard Rotella 15W-40 about 1.5 years ago to the Amsoil 15W-40, and was the best thing I could have done! Though some of the new diesels are rated for 7500 mile oil changes, when using Rotella I still changed it every 3k miles. With the new emissions on these trucks, the regular oil doesn't last near as long. After only 3k miles, the oil was almost as thin as water, and the lubricity was nearly gone.
After switching to Amsoil, I can go the full 7500 miles and then some (with oil analysis), and the oil still feels like new. I have since started using Amsoil to replace all the fluids in my truck.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Underwaydayz: space

Great Product

Amazing. I have noticeable temperature drops. I run it past the recommended oil change intervals, although that is not recommended. Combined with the Wix filter and it starts easy, runs cooler, and longer intervals. Not a single bad thing to say.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Oscar the Fishaholic: space

My Brother Convinced Me

My brother has owned an F250 Diesel for over 10 years. He told me that his truck performs the same as it did 10 years ago and he has had no fuel injector or motor problems. His friends have had those kinds of problems with their trucks. The difference he said is that he has been using AMSoil in this engine and transmission, and his friends did not. So when I bought my GMC 2500HD Diesel, I bought AMSoil for my truck. Their record is impressive. If I can trust my brother, who can I trust?

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Pete: space

I have used this oil since 1984.

I have used this oil in my own Cummins engines since 1996.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Happy Camper: space

Happy Camper!

I have been using Amsoil in my diesel towing vehicles sense 2004, when I purchased my first diesel GMC 2500 pickup. I tow a 10,000 pound Airstream Travel Trailer 10,000 to 15,000 miles a year, and change my oil one time each year. I have used an Amsoil Duai Filter System with the Bypass filter. I change the Full Flow Filter two times per year, and the Bypass filter one time. I got my oil analyzed each year just before my oil change for six years. I never had the lab recommend I change the oil. I put 125,000 miles om my first Amsoil truck, then sold it to a friend in 2014. The oil I am reviewing was bought for that friend, that is stil towing a Travel Trailer and changing the oil like I did.
I now have a 2015 Chevy 3500 Diesel set up just like my 2004 GMC was for Amsoil and dual filters. The order for this oil also included the oil and filters for my new truck. I look forward to getting the same results with this truck doing the same job.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by R.V. Transporter: space

The best oil out there!

I use Amsoil in my 2015 F-250. This oil holds up under the stresses that come with running 11 hrs. a day 5 days a week in commercial use. My 2015 already has 155k miles on it thanks to Amsoil, without any engine problems. I have tried other oils, even Royal Purple Duralec, but none compare to the 15-40's strengths when under the high temperatures of Summer in the south and the cold temperatures of the north in Winter.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Bryan: space

I put nothing but Amsoil in my vehicles

I have been using Amsoil for many years I use nothing but Amsoil in my vehicles I have a Duramax diesel 6.6 2011 In my opinion Amsoil is the best synthetic oil on the market .

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

A Verified Buyer is an individual who has purchased the reviewed product and submitted their review through a specific process that tracks purchase history.Reviewed by Smart business owner: space

Top quality products con artists distributor

Have used amsoil but stopped because the distributor was trying to get me to invest into get rich quick schemes

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)

Reviewed by Bill Ward: space

Oil of choice for my Duramax

I am using the 15W-40 Premium Synthetic from AMSOIL right from new, enjoying extended drains and great fuel mileage. The truck is 9 months old and has 87,000 km already, also switched the transmission and diffs over to AMSOIL.

Item Reviewed: Signature Series Max-Duty Synthetic CK-4 Diesel Oil 15W-40 (DME)
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