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Customer Ratings & Reviews

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SAE 15W-40 Heavy-Duty Diesel and Marine Oil

Product code : AMEQT-EA

4.9 Read 207 reviews

Customer Rating

4.9

78% would recommend

  • 5 196
  • 4 10
  • 3 1
  • 2 0
  • 1 0

SAE 15W-40 Heavy-Duty Diesel and Marine Oil

4.9 Based on 207 reviews
  • 5
    Best for any engine--especially older ones
    By  WILLIAM,  a  Verified Buyer  from  Arizona  on  February 26, 2021

    Describe the issue

    This is probably the best in the world.
  • 5
    By  BRIAN,  a  Verified Buyer  from  Utah  on  February 15, 2021

    Describe the issue

    I work my Diesel hard towing doubles in the mountains you can always count on Amsoil to protect your engine
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  Ben,  a  Verified Buyer  from  Ingleside, Ontario, Canada  on  February 10, 2021

    Describe the issue

    Have used this product since 1997, and still impress with it. Do oil change once a year (approx 25000 kilometers per yr) send an oil sample to Lab and return are excellent. Highly recommended
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    ByPass Filter oil
    By  Robert,  a  Verified Buyer  from  Washington  on  January 30, 2021

    Describe the issue

  • 5
    15/40marine diesel
    By  John,  a  Verified Buyer  from  Keremeos. Bc, Canada   on  January 29, 2021

    Describe the issue

    I have been using this engine oil in my Diesel Pusher Motor coach for 10 years and would not use another oil. I also have the Turbo Drive automatic oil in Allison Transmission and because this transmission is not only very good but it is an expensive one that I only want the best oil in it. I actually replaced the recommended Castrol Transynd oil that was in it to this Amsoil one and noticed that the shifting is smoother and the temperatures are lower during use. I monitor all the engine and transmission activity thru a computer while driving so I actually am seeing what is happening at any time, so, these issues I see and not only feel.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  JIM,  a  Verified Buyer  from  simi valley, ca  on  January 25, 2021

    Describe the issue

    I have been running this oil for 15 years in my 2005 superduty 6.0 diesel. This truck pulls a 16,000 lb fifthwheel many miles a year. Engine does not use any oil, have not had any injector sticking, and no turbo coking. Great customer service and lighting fast shipping.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  HAL,  a  Verified Buyer  from  lake havasu city az. 86404  on  January 08, 2021

    Describe the issue

    I have been using amsoil diesel/marine in my 2004 dodge cummins since it was new, never had any issues. the truck has 186000 miles on it and sometimes the oil doese't get changed for 6000 miles but always has plenty of lubricity when changed. Hal
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    better for cold starts
    By  DERICK,  a  Verified Buyer  from  Virginia  on  January 08, 2021

    Describe the issue

    I have a Kubota 8200 farm tractor it has a low oil pressure shut-off in cold weather using conventional motor oil same weight it would crank and shut off using Amsoil diesel marine this stopped so oil is getting through the engine quicker so now I use in all our farm equipment
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    Nothing but the best
    By  FIN,  a  Verified Buyer  from  Florida  on  January 01, 2021

    Describe the issue

    The absolute best for my 2002 7.3L Diesel Excursion.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  JOSEPH,  a  Verified Buyer  on  December 05, 2020

    Describe the issue

    Great oil, I use it in my 2006 Century Freightliner, I have over a million miles on it. Wouldn't trust any other oil.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  KENNETH,  a  Verified Buyer  on  December 01, 2020

    Describe the issue

    I have a Chevy Silverado 3500 year 2008 410,000 miles on the truck love this product
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  PAUL,  a  Verified Buyer  on  November 17, 2020

    Describe the issue

    Over 200,000 miles on F-150 using this oil no issues what so ever with engine.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    By  Anonymous,  a  Verified Buyer  on  October 23, 2020

    Describe the issue

    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    Good Product
    By  Anonymous,  a  Verified Buyer  from  Belgrade, MT  on  October 19, 2020

    Describe the issue

    Have been running in 04 duramax 3/4 ton for 100,000 miles with regular oil change intervals between every 3500 to 5000 miles in a work truck that has towed heavy loads or been under stress for most of its life. Switched to synthetic amsoil at 65,000 miles in engine, plus transmission and all the boxes. Has 179,000 + miles on it now and is still running and working strong. I believe the amsoil and regular oil change intervals has made a difference in the longevity of trucks power train components.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    The... best oil for pre Anniston
    By  Anonymous,  a  Verified Buyer  on  October 15, 2020

    Describe the issue

    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    Best of the best
    By  RW,  a  Verified Buyer  from  Missouri  on  October 15, 2020

    Describe the issue

    I recommend AmsOil products all the time to friends and family. Well worth the investment.
    Bottom Line
    Yes, I would recommend this to a friend.
  • 5
    Good product
    By  Flint,  a  Verified Buyer  on  October 17, 2019

    Describe the issue

    it's a good product but I don't like the gallon jug design. They're hard to pour.
  • 5
    Have been using this oil for 15 years.
    By  Leslie,  a  Verified Buyer  on  October 16, 2019

    Describe the issue

    Have used this oil in my Duramax since it finally broke in at 70,000, I now have 255,000 on it and every oil test came with 50% oil life after 10,000. I do a lot of short trips along with really long trips towing.
  • 5
    Yes
    By  Corey,  a  Verified Buyer  on  October 10, 2019

    Describe the issue

    Makes changes a snap in my duramax. The 2 1/2 gallon jug fills her to the top of the stick. Great product and easy to order too
  • 5
    i have bought this oil since 2005 and will continue
    By  Billy,  a  Verified Buyer  on  October 08, 2019

    Describe the issue

    I have used amsoil in my 2003 dodge ram 3500 the oil, performs very well has always checked good with an oil analysis 222,000 miles without ant oil related problems towing horse trailers and now a 36ft 5th wheel