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Customer Ratings & Reviews

Signature Series Max-Duty Synthetic Diesel Oil 5W-40

Product code : DEOQT-EA

4.9 star rating Read 866 reviews

Customer Rating

4.9

88% would recommend

  • 5 821
  • 4 34
  • 3 3
  • 2 3
  • 1 5

Signature Series Max-Duty Synthetic Diesel Oil 5W-40

4.9 star rating Based on 866 reviews
  • 5 star rating
    Best oil
    By  ANTHONY,  a  Verified Buyer  from  Phoenix, AZ   on  January 31, 2022
    It's the best oil I've ever used, probably the best oil in the world!!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent oil
    By  MITCHELL,  a  Verified Buyer  from  Texas  on  January 29, 2022
    Only oil I will run in my 2019 Cummins!
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    DME 15W-40
    By  DUANE L.,  a  Verified Buyer  from  Covington PA  on  January 29, 2022
    Amsoil is one of the best oils on the market, after all AJ did make the first API synthetic oil. Instant oil pressure even when it's cold than 32 ferhenhiet.
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  • 5 star rating
    GREAT SERVICE/SHIPPING
    By  DAN,  a  Verified Buyer  from  NORTHERN IL  on  January 28, 2022
    1ST TIME USING PRODUCT SO FAR SO GOOD GREAT TO DEAL WITH
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent product!
    By  DANNY,  a  Verified Buyer  from  Illinois  on  January 26, 2022
    I immediately noticed a difference in the cold start being much easier and quieter. Will be using this oil from now on!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent product
    By  RICHARD,  a  Verified Buyer  from  NH  on  January 26, 2022
    Long lasting and good protection for your engine
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Awesome product!
    By  DAVID,  a  Verified Buyer  on  January 25, 2022
    We absolutely love Amsoil products! Amsoil protects all of our equipment. Diesel powered Ram, turbo cars and of course 4T in our Briggs powered Kart.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Truck
    By  ED,  a  Verified Buyer  from  Apopka  on  January 24, 2022
    Wow better mileage, cleaner motor and cooler by 10 degrees the using factory oil .
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best oil
    By  DANE,  a  Verified Buyer  on  January 22, 2022
    Amsoil is the only oil I will use for my vehicles.. it’s the best there is!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Quality product
    By  JEFF,  a  Verified Buyer  on  January 22, 2022
    Excellent product.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Signature Series Max Duty Diesel Oil 15w-40
    By  BILL,  a  Verified Buyer  from  Canada  on  January 18, 2022
    I have a 5.9 cummins ram with a fully built compound turbo set-up and Goerend transmission. The truck makes 800+ HP at the wheels and I drive it quite hard. I have only used and will only use Amsoil products for this build. I am 63 and and have seen and used different products over the decades. It is so nice to now just look at the Amsoil website and order what I need for whatever I am working on. I have always told my sons "oil is cheap, engines are expensive"
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    15W-40 oil
    By  LEONARD,  a  Verified Buyer  on  January 17, 2022
    This oil works great and protects my engine. It was easy to order and arrived quickly. Thanks
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Amazing oil
    By  HUSSAIN,  a  Verified Buyer  from  Burleson tx  on  January 16, 2022
    I ordered this oil because i saw very good amazing reviews and honestly its one of the best oils I've used in my truck gives great protection and great milage
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Happy long time customer
    By  BRUCE,  a  Verified Buyer  on  January 15, 2022
    I've been very happy with the customer service with Amsoil for a long time. Easy ordering, very fast shipping. I use their products in all my vehicles. I also use their products in my offshore boat.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Great 👍
    By  Goose,  a  Verified Buyer  from  British Columbia   on  January 15, 2022
    I started using amsoil 3 years ago after lots of research and found it to be the best. I use it for everything on my pickup.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 4 star rating
    Greatr
    By  DON,  a  Verified Buyer  from  Iowa  on  January 14, 2022
    I've run Amsoil in my 6.6 Duramax in screaming hot and sub zero temps with no issues at all. I intend to continue to use it.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Good oil
    By  JARED,  a  Verified Buyer  on  January 13, 2022
    Its a good oil but i was surprised i didnt get any stickers. When i bought it previously i got stickers
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Very fast shipping
    By  Chad,  a  Verified Buyer  from  Utah  on  January 12, 2022
    Awesome shipping time!!
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5 star rating
    Great Product
    By  BRETT,  a  Verified Buyer  from  Cocoa,FL.  on  January 10, 2022
    I have used AMSOIL in my Ford diesel for 15 plus years and still going strong at over 444k miles!
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  • 5 star rating
    Best thing on the shelf
    By  JEFF,  a  Verified Buyer  from  Unfortunately California  on  January 09, 2022
    This is the only thing I have put in my truck seance I have owned my it.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?