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

Product code : DEOQT-EA

4.9 star rating Read 1,158 reviews

Customer Rating

4.9

91% would recommend

  • 5 1105
  • 4 40
  • 3 4
  • 2 3
  • 1 6

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

4.9 star rating Based on 1,158 reviews
  • 5 star rating
    Diesel oil
    By  BART,  a  Verified Buyer  from  Puerto San Carlos, Baja Sur  on  November 06, 2023
    Been using this oil in my Chevy Silverado and have noticed an increase in mpg and money savings due to the extended life of the product and not needing to change oil as often.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best Oil Out There
    By  JIM,  a  Verified Buyer  from  Destin Florida  on  November 05, 2023
    Have been using Amsoil for the past two diesel trucks i've had the one i have now i had a head gasket problem. When I pulled the motor apart the cylinders still had the factory crosshatches and that is with 125,000 miles on it !!!!!!!!!! So I will be using nothing else in my vehicles and have turned alot of my friends on to Amsoil. Thanks for making such a great product !!!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel oil
    By  GARY,  a  Verified Buyer  from  Seguin,TX  on  November 04, 2023
    I have used Amsoil oil in my vehicles for over 20yrs and have had tremendous luck with it. No engine problems at all. I am now using the diesel oil and am having the same results. I constantly recommend Amsoil to people I know and talk to.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel oil
    By  ED,  a  Verified Buyer  on  November 01, 2023
    Still the same would not use anything else in my Diesel engine
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Rotella
    By  JOSH,  a  Verified Buyer  on  October 31, 2023
    was using rotella an truck was smoking Switched to amsoil and it quit
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Was using rotella
    By  JOSH,  a  Verified Buyer  on  October 21, 2023
    Started using amsoil truck runs so much better and doesn’t burn the oil like rotella
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 4 star rating
    Good oil. Wish it were also available in the bags
    By  JARED,  a  Verified Buyer  from  Colorado  on  October 21, 2023
    Always a great product. I wish it were available in those bags. That is a far superior container than these jugs.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Amazing motor oil
    By  GREG,  a  Verified Buyer  on  October 19, 2023
    Been running this in my 2004.5 ram 2500 Cummins for several years now. Tried other oils and it runs hot with AMSOIL in runs 20 to 30 degrees cooler. Great product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best Oil Ever
    By  RALPH,  a  Verified Buyer  from  Stanley, North Carolina   on  October 17, 2023
    Amsoil is the only oil I put in all my Diesel engines. I love the next day delivery I will be a lifelong customer
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best oil I have used in my Duramax.
    By  DANIEL,  a  Verified Buyer  from  Maryland   on  October 15, 2023
    No oil beside AMSOIL Heavy Duty makes my truck run the way it does.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Amsoil for diesel engines
    By  RICHARD,  a  Verified Buyer  from  Alberta Canada   on  October 15, 2023
    I use amsoil in both diesel trucks and in my diesel welding machine
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Simply the best oil
    By  MICHAEL,  a  Verified Buyer  from  Quebec Canada  on  October 12, 2023
    This "magic" oil reduce by half the engine oil consumption of my truck!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great
    By  JOE,  a  Verified Buyer  from  Texas  on  October 09, 2023
    Great product been using it for years
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great Oil
    By  ASHTON,  a  Verified Buyer  from  Arkansas  on  October 06, 2023
    I’ve been using this stuff for a few years now on my Cummins and I strongly believe this is the best oil on the market.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    All I can say is Wow!!
    By  BRIAN,  a  Verified Buyer  from  Denver  on  October 01, 2023
    I use Amsoil in my cars and motorcycles and just tried in my semi truck. Can’t believe the difference over other major brands. I was disappointed major brands because I do long oil intervals changed with my ops filter and oil test every 25000 miles. The major brands I couldn’t keep the base up to where it needed to be. I will update on my lab test on Amsoil after 25k . Plus my fuel mileage went up one tenth. We will see if this continues
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Beast oil
    By  MICHAEL,  a  Verified Buyer  from  Wilmington  on  September 29, 2023
    Will use anything else
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great oil for my Cummins
    By  KENNETH,  a  Verified Buyer  on  September 12, 2023
    Switched over from Royal Purple and could not be happier.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great diesel oil
    By  DANO,  a  Verified Buyer  on  September 11, 2023
    All usual Amsoil doesn't disappoint. Great oil for Ram 6.7, and there deliveries rapid. Will always buy my oils from Amsoil
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Good stuff
    By  RONNIE,  a  Verified Buyer  on  September 08, 2023
    Worth the money
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Long lasting
    By  LUCY,  a  Verified Buyer  from  Killeen, Texas  on  September 08, 2023
    Quality stuff here. Long lasting good quality oil. A bit pricey but you get what you pay for
    Bottom Line
    Yes, I would recommend this to a friend.
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