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

Product code : DMEQTC-EA

4.9 star rating Read 1,156 reviews

Customer Rating

4.9

91% would recommend

  • 5 1103
  • 4 40
  • 3 4
  • 2 3
  • 1 6

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

4.9 star rating Based on 1,156 reviews
  • 5 star rating
    Best oil on the market
    By  JOSEPH,  a  Verified Buyer  from  S.W. Missouri   on  April 16, 2024
    Best you can buy. Can't beat it. I use Amsoil in all 4 vehicles and always will.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great stuff
    By  JEFF,  a  Verified Buyer  from  Idaho  on  April 16, 2024
    I was introduced to Amsoil and there products and glad so far I made the switch from Mobile. Will see how it it goes when I pull the 5th wheel RV next week.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Extreme duty
    By  CHRIS,  a  Verified Buyer  from  Roosevelt Utah  on  April 13, 2024
    Oil field, off road, 129,000 lbs, and on road grades up to 8%, off road grades up to 16%, pulling a super set of 108’ in combination length. The truck is a 2019 Peterbilt 389 with a 565 x15 Cummins, 18spd manual, 3:90 rear ends and lockers inside 23,000 lb housings. To date, the engine oil has been replaced with the 15w40 signature series as well as the Amsoil bypass system. The engine coolant has also been replaced with the Amsoil 1,000,000 mile coolant and the differential fluids have also been changed to the Amsoil Severe gear 100% synthetic 75w140. Under these extreme conditions, these Amsoil products are providing exceptional performance and durability. My truck is not building heat from friction caused by wear. The other drivers I work with are already complaining about their trucks building heat from the coolant temperatures to engine oil temperatures to differential temperatures. I have no such complaints. These products are truly the BEST in synthetics. Thanks Amsoil for keeping my truck on and off road and out of the shops
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    AMSOIL Signature Series 0W-40 100% Synthetic Max-Duty Diesel
    By  Eugene,  a  Verified Buyer  from  Brooklyn, NY  on  April 11, 2024
    Winter time mixing with other AMS oils. Working very good.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Quality oil.
    By  MARK,  a  Verified Buyer  from  Massachusetts  on  April 11, 2024
    I like the data backed science behind the amsoil products. I have had my amsoil analyzed by independent third party companies after various mileage intervals (5k, 10k and 20k+) and the oil still had good lubrication characteristics (tbn) at even 20k+ miles.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best in its class
    By  TRACY,  a  Verified Buyer  from  Clarksville   on  April 09, 2024
    Can’t beat this stuff I run it in my F350
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil change
    By  NICK,  a  Verified Buyer  from  Key largo   on  April 09, 2024
    Smooth and easy Send my promotional product. That I asked for 3 times... Let's see if I get a response.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great Quality
    By  SOLOMON,  a  Verified Buyer  on  April 08, 2024
    Good oil buy it
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Better cold weather cranking
    By  DAVE,  a  Verified Buyer  from  Idaho  on  March 31, 2024
    Much better starting in the morning on cold winter days. I don’t drive it very often now so I change the oil only once a year with this oil. That’s less than 5000 miles.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    5w40 signature series
    By  CHRISTOPHER,  a  Verified Buyer  from  STL, Missouri  on  March 29, 2024
    Been running in my 05’ 6.0 powerstroke and have great results
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great product
    By  CHRIS,  a  Verified Buyer  from  GA  on  March 24, 2024
    No issues for 20 years. I have used this product and will Continue to
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Great motor oil for diesel pickups
    By  WADE,  a  Verified Buyer  from  Texas  on  March 22, 2024
    I have been using Amsoil now for 2yrs straight. I started using this motor oil with my F350 dually, and also use the Amsoil 20micron filter. So far so good. I have seen the oil retain its viscosity better during my regular oil change frequency as compared to the Rotella T I was using (NOTE: Rotella T is great oil also). As a result, I have become an Amsoil convert. Am still sticking to the traditional Ford oil change frequency that is estimated by the truck's onboard computer (approx 7000mi), for the simple reason that oil is relatively cheap when compared to the price of a failed engine. :-) Last, from the information I have read I do think that Amsoil will extend the life of my engine (currently at approximately 160,000mi).
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    So far so good
    By  JOSHUA,  a  Verified Buyer  from  Oregon  on  March 16, 2024
    Lightning fast shipping! Great motor oil. Says you can use it for extended mileage, altho when I change my oil I can feel and hear the Motor running quieter and it feels smoother. Maybe thats a filter thing but I don't push it that far past OM recommendations. I bout my 2018 Ram with the Cummins in 2019 with 420 miles on it and this is the only oil I have used! Got 170k on it now. It's completely stock. I use the Stratapore filter by fleetguard.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Amsoil Diesel oil
    By  SCOTT,  a  Verified Buyer  from  North Central Kansas  on  March 12, 2024
    I have been using Amsoil Diesel oil since I started farming and bought my first tractor, a used JD 4430 in 1979. That tractor is still used in my farming operation. It still does not use any oil, starts better in cold weather, and has been less expensive to maintain by far than neighbors using even other brands of synthetic oils.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil
    By  WILLIAM,  a  Verified Buyer  on  March 09, 2024
    Great oil, been using from day one ever since I bought my truck brand new!
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Best Oil for my BMW Twin-Turbo
    By  JIM,  a  Verified Buyer  from  Shelbyville, TN  on  March 09, 2024
    I only run Amsoil Signature Series in my Twin-Turbo BMW X5s. I run them pretty hard and keep them serviced every 6000 miles and NO problems ever-Thanks! Jim
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Oil
    By  DAN,  a  Verified Buyer  on  March 09, 2024
    Good product
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Worth the money over conventional oils!
    By  CHRISTIAN,  a  Verified Buyer  from  Oklahoma  on  March 05, 2024
    I've been a diesel tech, boat tech and advisor for years now. I started using AMSOIL in my 00 7.3l a long time ago, I noticed smoother injector operation and better response. Since then, AMSOIL is in all of my diesels! My 19 model SuperDuty feels more free and helps with response and keeping decent mileage. I use the filters as well! I will continue using AMSOIL over typical conventional oils, thanks AMSOIL for a great product.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Ram 2500
    By  JOE,  a  Verified Buyer  from  North Carolina   on  March 04, 2024
    This is the only oil I would use.
    Bottom Line
    Yes, I would recommend this to a friend.
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  • 5 star rating
    Excellent oil for Duramax
    By  R,  a  Verified Buyer  on  March 03, 2024
    This oil has proven to be the best. It lasts longer and my engine sounds and runs amazing when I use it.
    Bottom Line
    Yes, I would recommend this to a friend.
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