Back

Close Icon

Main Menu

Your order may take longer than normal to arrive. We are experiencing extremely high demand and freight carriers are experiencing delays nationwide. LTL shipments are most severely affected.

Customer Ratings & Reviews

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

Product code : AMEQT-EA

4.9 Read 222 reviews

Customer Rating

4.9

80% would recommend

  • 5 210
  • 4 10
  • 3 2
  • 2 0
  • 1 0

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

4.9 Based on 222 reviews
  • 5
    Great high quality product
    By  Rod,  a  Verified Buyer  from  MI  on  October 19, 2021

    Describe the issue

    Fast shipping great quality!
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Awesome
    By  MATTHEW,  a  Verified Buyer  on  October 17, 2021

    Describe the issue

    Fast shipping great product
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    15w-40 Diesel/Marine OIl
    By  BEN,  a  Verified Buyer  from  Tulsa  on  September 16, 2021

    Describe the issue

    I have used this oil for many, many years in my 1985 Mercedes Benz 300SD Turbo Diesel and my 1951 John Deere Model R diesel tractor engine with excellent results. Zero failures
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Series 3000 - 5w-30
    By  BEN,  a  Verified Buyer  from  Tulsa  on  September 16, 2021

    Describe the issue

    This is the best oil for my 2004 John Deere X495 diesel tractor, the pony motor on my 1951 John Deere Model R diesel tractor and all my smaller 4 cycle gasoline engines. Been using it in these applications for years and years with excellent results and zero engine failures.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 3
    Oil life
    By  ROBERT,  a  Verified Buyer  from  Edgewater,(Maryland)   on  September 13, 2021

    Describe the issue

    This oil seems to break down at approximately 125 hours. The oil turned black and got really thin. This caused my oil pressure to drop 7-10 lbs. I’m going to give it one more try before I witch brands. This oil is being used in a Cummins 5.9QSB that is in my boat and they recommend 250 hour oil changes. This oil will never make it that long. Thank you for your time.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    The only oil i will use in my truck
    By  SCOTT,  a  Verified Buyer  from  Houston  on  September 05, 2021

    Describe the issue

    I have used amsoil in my 5.9 cummins for 11 years now. 230k miles and performs like it is new.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    GMC Duramax 6.5 LBZ (2007)
    By  TED,  a  Verified Buyer  from  Colorado   on  August 25, 2021

    Describe the issue

    Run this in my 2007 pre-DEF engine since new. First ran for 15K and then tested results with SOAP analysis—results were excellent. Now run the oil at least 30K miles, changing filters every 15K. Good MPG and cold wx starts to 0 degrees F. Highly recommend for towing and tough engine use conditions.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Great diesel oil for pre-dpf engines
    By  ALEK J,  a  Verified Buyer  from  NC  on  July 30, 2021

    Describe the issue

    I've been using this oil nearly exclusively for the past 15 years in my 2006 Duramax. I average 35,000 miles between oil changes and monitor every 10-12k miles when I change the filters. Amsoil has always provided great protection for my engine. The high TBN lets me use the oil longer than any conventional oil and my truck is running great with 256,000+ miles. Great oil, I'll continue to use it.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    20+ Years
    By  KIT,  a  Verified Buyer  from  Marysville, WA  on  July 30, 2021

    Describe the issue

    This is all I have used in my 97 Ford F-350 Powerstroke. Formulated especially for these motors.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Going for 50,000 mi
    By  ALEK J,  a  Verified Buyer  from  NC  on  July 11, 2021

    Describe the issue

    I’ve been using this oil for 15 years with excellent results. High TBN promotes its use for extended oil change intervals. I’ve run several 40,000 mi intervals. Just added the PPE oil pan and filter adding an extra 2qt capacity to the engine, and draining 99% of the old oil. Hoping to get 50,000 mi on this oil!
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Great oil for a deisel
    By  LES C.,  a  Verified Buyer  from  Colorado  on  June 20, 2021

    Describe the issue

    Have been using this oil since the engine was broken in, now have 276,000 miles on it and still going strong.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    287,000 miles using this oil
    By  DAN,  a  Verified Buyer  from  CA  on  May 25, 2021

    Describe the issue

    I've been using the 15-40 Heavy-Duty Diesel and Marine oil in my 2006 GMC 2500 HD Duramax LBZ since I bought it new and now have 287,00 miles on it and many of those miles towing heavy loads in the heat.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Better than Expected
    By  Cambren,  a  Verified Buyer  from  FL  on  May 21, 2021

    Describe the issue

    I used this in my marine diesel engine. I had some reservations based on past experience with synthetic diesel oil from another manufacturer (noisy operation), but this far exceeded my expectations. Since switching from the industry standard mineral based oil to Amsoil Heavy Duty and Marine Diesel Oil, I have higher oil pressure and cooler operating temps, and the noise level seems lower as well. I am very satisfied.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    01’ F250 7.3l Platinum Edition 400k miles
    By  RONNEY,  a  Verified Buyer  from  Texas  on  May 07, 2021

    Describe the issue

    Folks, I switched to Amsoil at 150,000 miles now I have 400,000 miles on my truck. I believe the quality of Amsoil and there filters are keeping the engine wear down. My last Blackstone oil sample (paraphrasing here) recommended I increase oil change intervals if desired because the sample indicates an engine of around 130,000 miles. I especially enjoy the the super quick delivery to my doorstep.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    Great oil that works
    By  Richard,  a  Verified Buyer  from  CT  on  April 08, 2021

    Describe the issue

    I changed the oil in my 2010 F 150 to Amsoil and the gas millage has increased by by 4 miles to the gal. I am very happy with the new oil and will keep a eye on the millage to see if it stays good
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 5
    excellent oil
    By  BRYAN,  a  Verified Buyer  from  ND  on  March 06, 2021

    Describe the issue

    i use this oil in my 8030 allis-chalmers tractor. this synthetic oil is excellent we get to 20 below zero here in the winter and i use this tractor on the snowblower and the minute the tractor makes one revolution with the starter the oil pressure light is off and it starts way easier with this oil. i am very satisfied with this product. would recommend to anybody who would want to use it. super product.
    Bottom Line
    Yes, I would recommend this to a friend.
    Was this review helpful?
  • 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.
    Was this review helpful?
  • 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.
    Was this review helpful?
  • 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.
    Was this review helpful?
  • 5
    ByPass Filter oil
    By  Robert,  a  Verified Buyer  from  Washington  on  January 30, 2021

    Describe the issue

    Was this review helpful?