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AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

Product code : DMEQT-EA

  • Outstanding extreme-pressure protection
  • Delivers 6X more wear protection1
  • Maintains proper viscosity (thickness) 
  • Minimizes oil consumption
  • Maximizes fuel efficiency
  • Excels in extreme temperatures 
  • Confidently extend drain intervals

     

    1Based on third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using 5W-30 as worst-case representation

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AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil



Developed to protect the horsepower diesel enthusiasts crave and extend the life of hard-working commercial equipment in the most severe conditions. Signature Series synthetic technology delivers max-duty protection in on- and off-road applications.

See the Product Data Bulletin for full details.

MAXIMUM ENGINE PROTECTION

  • Delivers 6X more wear protection,1 delivering extra protection so you can push your diesel with peace of mind
  • Provides long-lasting wear protection, keeping cylinder liners looking like new2
  • Delivers up to 60 percent better turbo cleanliness3
  • Withstands the extra demands you place on the turbo when pulling heavy loads or updating the tune for maximum horsepower
  • Provides up to 2X better rust protection4

1Based on third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using 5W-30 as worst-case representation
2Based on independent testing of AMSOIL 5W-30 Signature Series Max-Duty Synthetic Diesel Oil and a leading conventional 15W-40 diesel oil using the Detroit Diesel* DD13 Scuffing test for specification DFS 93K222.
3Based on specification standards of CAT C13 2nd Ring Top Land Carbon testing
4Based on industry standard testing using the NMMA FC-W Rust Test.


Delivers More Wear Protection

Third-party testing shows Signature Series Max-Duty Synthetic Diesel Oil delivers 6X more protection against wear than required by Detroit Diesel’s* standard.II

IIBased on third-party testing in the Detroit Diesel DD13 Scuffing Test for specification DFS 93K222 using 5W-30 as worst-case representation.
*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use.


AMSOIL Fights Wear

AMSOIL delivers powerful engine protection. How good is it? In third-party testing compared to a leading brand, AMSOIL provided long-lasting wear protection, keeping cylinder liners looking like new.DD

AMSOIL Fights Wear – AMSOIL delivers powerful engine protection. How good is it? In third-party testing compared to a leading brand, AMSOIL provided long-lasting wear protection, keeping cylinder liners looking like new.

DDBased on third-party testing of AMSOIL 5W-30 Signature Series Max-Duty Synthetic Diesel Oil and a leading conventional 15W-40 diesel oil using the Detroit Diesel* DD13 Scuffing test for specification DFS 93K222.
*All trademarked names and images are the property of their respective owners and may be registered marks in some countries. No affiliation or endorsement claim, express or implied, is made by their use.


Keeps Turbos Clean

AMSOIL Signature Series Max-Duty Synthetic Diesel Oil provides protection boosted to the max, delivering up to 60% better turbo cleanlinessJ and withstanding the extra demands you place on the turbo when pulling heavy loads or updating the tune for maximum horsepower.

JBased on specification standards of CAT C13 2nd Ring Top Land Carbon testing


Protects Against Rust

Provides up to 2X better rust protection.K Protects Against Rust – Provides up to 2X better rust protection.

KBased on industry standard testing using the NMMA FC-W Rust Test.


VISCOSITY CONTROL

  • Resists oxidation and the thickening effects of soot contamination
  • Retains viscosity after high-temperature service for maximum engine protection and efficiency
  • Provides up to 76 percent less oil consumption5

5Than required by the API CK-4 standard in the Caterpillar-1N oil consumption test


Reduces Oil Consumption

Signature Series Max-Duty Synthetic Diesel Oil provides up to 76% less oil consumption.L

Reduces Oil Consumption – Signature Series Max-Duty Synthetic Diesel Oil provides up to 76% less oil consumption.

LThan required by the API CK-4 standard in the Caterpillar-1N oil consumption test.


EXCELS IN EXTREME TEMPERATURES

  • Provides outstanding protection and performance in hot and cold temperature extremes
  • Resists thermal (heat) breakdown better than conventional and competing synthetic diesel oils.
  • Stays fluid in sub-zero temperatures for easier starting, improved oil flow and reduced wear.

See the Product Data Bulletin for full details.

AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

Data Bulletin

Warranty

SDS



AMSOIL Signature Series 15W-40 100% Synthetic Max-Duty Diesel Oil

  • 5 star rating
    Pickup truck oil
    By  JEFF,  a  Verified Buyer  from  West Central Illinois  on  January 21, 2025
    I think the AMSOIL is the best oil on the market. The shipping is very fast. I usually receive the product the next day.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Great oil
    By  MACK,  a  Verified Buyer  from  KS  on  January 21, 2025
    I have been using Amsoil for years now. The oil life and ease of getting it is great! I had my order delivered the next day after I ordered it.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Diesel motor oil
    By  NATE,  a  Verified Buyer  from  Eden  on  January 19, 2025
    My 2004 Cummins runs flawlessly with this motor oil
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Amsoil Diesel Oil
    By  BRENT,  a  Verified Buyer  from  KC  on  January 18, 2025
    Best oil made, PERIOD. I’ve used it my whole life and it never lets me down. A++
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Quiet down a 6.7l ford
    By  BMAC,  a  Verified Buyer  from  Drayton Valley  on  January 17, 2025
    I have used the heavy duty oil from amsoil, which is great protection. Motor was still little noisy, and switched oil to this signature series and made the motor quiet down alot and run smooth. It's a good one to run.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Great Oil
    By  MICHAEL,  a  Verified Buyer  from  Lancaster, SC  on  January 16, 2025
    I use to use Rotella T5 10W30 and was getting decent mileage and protection. When Shell couldn't get the additives to make the T5 oil I changed to Amsoil 10W30. Best decision I could have made! The oil gets me about .5 to 1 mpg increase. I love this oil! I'm glad I switched and don't plan on ever going back!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great stuff!
    By  CHARLIE,  a  Verified Buyer  on  January 14, 2025
    Love this oil.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Newer Diesels
    By  CURTIS,  a  Verified Buyer  on  January 09, 2025
    I just bought a newer diesel 5th wheel hauler to replace our aged 2002 Duramax. The old truck only used Amsoil 15w-40 Marine Diesel Oil. The new truck takes 5w-40 full synthetic or 10w-30. Since the marine grade doesn’t come in 5w-40, I used the signature series. Looking forward to many years with this new truck using Amsoil.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    AMSOIL Signature 5W-40 Synthetic Max-Duty Diesel Oil
    By  JOHN,  a  Verified Buyer  from  KS  on  January 08, 2025
    I began using the Signature 5W-40 Synthetic Max-Duty Diesel Oil in my 2024 New Ford F-350 with the new HO Diesel engine this past fall. I manage a large farm in Central KS and work in very extreme conditions. I’ve been more than happy with it’s performance and trust AMSOIL superior products will protect my engine for a long, long time.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Premium oil
    By  JEFF,  a  Verified Buyer  from  AZ  on  January 06, 2025
    Arrived quick. Great customer service.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?