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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
    A soul Products
    By  JAMES,  a  Verified Buyer  from  Lebanon Virginia   on  January 11, 2024
    I’ve purchased these products for my motorcycle and diesel truck. Love it. From oil to fuel additive and gear oils. Great Product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 3 star rating
    Good product
    By  Ron,  a  Verified Buyer  from  TN  on  January 11, 2024
    Great product but the price is becoming ridiculous. I will probably be looking for an alternative soon.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Max protection 6X
    By  WILBURN,  a  Verified Buyer  from  Texas  on  January 09, 2024
    Excellent diesel oil with max protection
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    What a difference
    By  RICHARD,  a  Verified Buyer  from  Payson az  on  January 09, 2024
    Difference is unbelievably a huge upgrade in performance and protection, engine is running smoother and starts easier especially where I live it’s been 12 degrees at night even though I use my block heater I’ve noticed a huge difference in starting, before Amsoil I used only rotella t-6 full synthetic and I’ve always changed my oil every 5,000 miles, I’m a preventive maintenance person and I’ve noticed my last few oil changes the oil was really thin and it just didn’t sit well with me. I only drive about 10, 000 miles a year so it will be nice to only change it once a year.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Used since new, never had an issue
    By  CHAD,  a  Verified Buyer  from  MN  on  January 08, 2024
    I’ve used AMSOIL products on all our vehicles since new and have never had any issues. Would recommend to anyone
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Sig. Series 5W-40 100% SYN Max-Duty Diesel Oil
    By  RICK,  a  Verified Buyer  from  Florida  on  January 07, 2024
    after Break-in period of a rebuilt Manufactured 6.7L started using Max-Duty and can tell it's a high-quality oil, by sound, etc.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil
    By  JOHN,  a  Verified Buyer  on  January 06, 2024
    I ise amsoil. My truck is still running. It must be working ok.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    04 Duramax
    By  TERRY,  a  Verified Buyer  on  January 04, 2024
    Best oil money can buy!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best there is
    By  ARIC,  a  Verified Buyer  from  Fresno Calif.  on  January 03, 2024
    I cant say enough about this oil. Its the best you can get.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Always Excellent Service
    By  ROBERT,  a  Verified Buyer  from  Seguin, Texas  on  January 03, 2024
    The product speaks for itself, however being able to order it and have it on my door step within a few days at no additional cost is amazing!!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel Oil
    By  EVERETT,  a  Verified Buyer  from  Herington   on  January 02, 2024
    Oil is the best available that's why I use it.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great stuff
    By  MATTHEW,  a  Verified Buyer  from  Ohio  on  January 02, 2024
    Fist time buyer, so far no complaints
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great product
    By  PATRICK,  a  Verified Buyer  from  Wichita, KS  on  January 02, 2024
    Great product, I use it in all my deisel trucks (4) and also in my older tractors (6). It last at least a year in most of my trucks, before I change it
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Trust
    By  HAPPY ,  a  Verified Buyer  from  Indiana  on  January 02, 2024
    I trust this product in my 2007 chevy 2500hd LMM duramax.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Thumbs up
    By  BENJAMIN,  a  Verified Buyer  on  December 29, 2023
    You already know!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent as always
    By  MATTHEW,  a  Verified Buyer  from  Vermont  on  December 28, 2023
    I just changed out 5W-40 for the 15W-40 recommended for the Chevy Duramax 2500. Perhaps I should have stayed with the 5W-40 for the colder weather. Somewhat unrelated but when I bought the truck two years ago, I had bad torque converter slap. So much so I thought there was something wrong with the engine mounts. I changed transmission fluid to AMSOIL and have not experienced the torque converter slap at all. Amsoil products are excellent.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best oil on the market
    By  JOSEPH,  a  Verified Buyer  from  S.W. Missouri   on  December 26, 2023
    5w flows better than 15w in the winter and gets where it needs to faster but the quality synthetic oil properties protect better than others even in the hot summer months. I won't use anything else. Have a 5.9 and a 6.7 and I use this in both.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Diesel oil
    By  CHRIS,  a  Verified Buyer  from  Oklahoma   on  December 18, 2023
    Never had an issue
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Too much packaging
    By  MICHAEL,  a  Verified Buyer  on  December 15, 2023
    Not sure why when you order an oil change kit for a 6 L diesel you get 15 quarts individually. I know you make a 10 quart jug. Wouldn’t it be easier to send that and then five single quarts or some other grouping of packaging?
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    I’m a believer
    By  MICHAEL,  a  Verified Buyer  from  Houston, TX   on  December 14, 2023
    I was very skeptical when a fellow driver told me that he uses this brand and how awesome it is, how he doesn’t have to change his oil as regularl as I did and on and on! I took a shot and am extremely impressed with the way my vehicle runs and the fact that I don’t have to change my oil at every 10,000 miles, this oil allows more and oil changes are maybe at 12-15,000! I will no other oil from here on out!
    Bottom Line
    Yes, I would recommend this to a friend.
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