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AMSOIL Signature Series 5W-40 100% Synthetic Max-Duty Diesel Oil

Product code : DEOQT-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 5W-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 5W-40 100% Synthetic Max-Duty Diesel Oil

Data Bulletin

Warranty

SDS



AMSOIL Signature Series 5W-40 100% Synthetic Max-Duty Diesel Oil

  • 5 star rating
    review
    By  NEIL,  a  Verified Buyer  from  CA  on  March 24, 2025
    great transaction , great product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    No complaints
    By  ELI,  a  Verified Buyer  on  March 24, 2025
    Oil change every 5k, it’s served me well.
    Bottom Line
    No, I would not recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Peace of mind
    By  PATRICK,  a  Verified Buyer  on  March 17, 2025
    Keep my business running without a worry
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Oil
    By  TIMOTHY,  a  Verified Buyer  on  March 15, 2025
    Great product fast shipping
    Was this review helpful?
  • 5 star rating
    Best diesel oil on the market by a mile.
    By  RYAN,  a  Verified Buyer  from  Lookout mountain Georgia   on  March 15, 2025
    Run 35k changes on the cummins running this a amsoil ea080 and the amsoil large bypass system. Last truck got 1.3 million miles on all original cummins 6.7 engine .
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best engine Oil ever
    By  STURE,  a  Verified Buyer  from  MN  on  March 14, 2025
    I am so pleased with this oil for my truck.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    15-40 diesel oil
    By  TONY,  a  Verified Buyer  on  March 14, 2025
    I have used this oil for the last 10 years in a 2015 duramax. I work the truck every day and have 209k miles on the truck. The truck doesn’t use any oil between its 7500 mile oil changes and still runs like new. I recommend giving it a try.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Amsoil oil
    By  MICHAEL,  a  Verified Buyer  from  Texas  on  March 14, 2025
    I used Amsoil in the 1980’s back then you had to know someone that sold it. Now we can order it online, it’s costly but I use it until I reach 12000-15000 miles which is usually about a year and a half. I trust the brand. I keep a spare case on hand.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    top notch product
    By  JOHN,  a  Verified Buyer  from  Tampa FL  on  March 13, 2025
    Good clean product.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Great oil used in my l5p duramax
    By  ROBERT,  a  Verified Buyer  from  Ohio  on  March 11, 2025
    Great oil , no complaints , it even got rid of the classic duramax type writer tick ! I'll never use another oil in it now that I've used this
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?