Product Reviewed: Synthetic Heavy-Duty Diesel & Marine Motor Oil SAE 15W-40 (AME)
Current Rating: 4.91 out of 5 stars
Votes & Reviews: 316 vote(s) and 236 user reviews.
Reviewed by duke: 
highly recommended
Reviewed by Chris:
I use this product in a 7.3 liter Powerstroke diesel engine. The formula works very well in my application - and the extended drain interval provided by oil analysis adds value to the protection.
Reviewed by Pete:
I use it in my 2004 Chev that has a 6.6l diesel
Reviewed by Denman:
Like product and use each year. Combined with bypass oil filter I change once a year. Oil sample sent in said oil still had lots of life left in it.
Reviewed by David:
I have used this in 2 of my 7.3 Powerstrokes, and have not had any lubrication problems.
Reviewed by banjo fred:
great product outlasts and out performs any oil i have ever used,i am a full-time rv er i pull a 5th wheel and boat from central il to the rio grande valley with a swing through eastern ky and back every year
Reviewed by Ray:
I change The oil Every 10,000 miles And when I send In the oil samples They always come back good. Have not had a need to change oil come back yet. For my diesel I would not run anything else.
Reviewed by Robo:
I have owned my Dodge Cummins Diesel Truck since new.
After the initial break-in, it has had nothing but Amsoil 15w-40 Heavy Duty Diesel and Marine Oil; and changed once a year; along with an Amsoil oil filter.
345,000 miles later should speak for itself.
Reviewed by Plattoon:
Been using it for 15 years . One of my old trucks which I sold to a friend after putting 100000 Amsoil miles on it now has over 300000 miles on it now. I used Amsoil in my race vehicles. Engine, diff ,transmission , brakes, grease...... Without ever having a failure. Great product.
Reviewed by Turtle:
I use this motor oil in a 2002 Ford Powerstroke 7.3 liter diesel E350 van equipped with Amsoil's dual oil filter system. With recommended filter change intervals, add-back oil, and regular oil analysis, I have yet to reach a point where I needed a complete oil drain and replacement. This system has saved me money and time and has provided great peace of mind. Plus it is very environmentally friendly because the old system using petroleum oil required disposing of 15 quarts of dirty, used oil every 3-5,000 miles.
Reviewed by Dave:
Would love to see an oil viscosity test kit with purchase of 25,000 mile filter. While I've used your product a lot, it's nice to see the results at the time of next oil change
Reviewed by Big nasty:
Cheaper and holds up better than royal purple
Reviewed by ans56:
I have used 15W-40 Heavy Duty Diesel and Marine Oil in all my diesel and heavy equipment. Amzoil has a fine product that can not be beat!
Reviewed by Dirty D:
Filled my 700 horse cummins and she purrs like a kitten. Sitting at 95000 miles since the build up and still smooth quiet idle and fantastic oil life. Would fully recommend this oil to anybody seeking simply the best!
Reviewed by Nick 0311:
Recently purchased 4 gallons for my 7.3 powerstroke & join the preferred customer program, couldn't be happier with my choice.
Reviewed by Travelworker:
Bought my diesel in 2004 brand new & put amsoil in when it just had 800 miles. Everybody said I should wait till all the seals broke in. Still have the truck 12 years later 131,000 miles no leaks & still use amsoil.
Reviewed by Gibby:
I use it in my older trucks one truck I bought used and replaced a rusted oil pan the motor was full of sludge. They ordered the wrong oil pan but need the truck so made it work for short time.it was on for maybe 1 and half months then changed to the right on. When I took it off the second time it looked like the motor was brand new I could see my reflection excellent product would recommend to everyone that can use it in there application
Reviewed by JasperFlash:
I have a 2002 F350 4 wheel drive 7.3 liter . I changed from regular oil to Amzoil at 10,000 miles . It now has 253,000 on it and no engine trouble that I attribute to Amzoil. It will last a lifetime using this oil . Had the valve covers pulled at 150,000 miles and there was no sludge buildup whatsoever. Can't say enough about this great product! If manufacturers would use this oil they would go broke because engines would last a lifetime!
Reviewed by Bob:
I have been using AMSOIL for years in my F350 Ford 7.3 diesel engine and never had any problems, and I love all the money I have saved over these years. I also use AMSOIL oil filter with each oil change. I am so pleased with AMSOIL products I be came a "Preferred Customer" and now planning to become a dealer.
Reviewed by Roger's GMC Diesel:
I started using Amsoil for my GMC Diesel in 2003 shortly after purchasing it. Works great and runs longer than the normal oil I had used on vehicles previously. My truck pulls horse trailers and is running great with over 230k miles and growing.
Reviewed by Farmer Bob:
I am a farmer and work my equipment hard and need the best of everything for the equipment so I get the most out of them and best performance.
Reviewed by Jack:
I am a long time customer with AMS oil, and highly recommend this product to everybody ,
Reviewed by Bean:
When I buy amsoil I know that it's the best. Don't even consider anything else. Been using it for 30 years not a problem with this oil. Kind of pricey but I know that it won't let me down.
Reviewed by Tapage:
I'm using this one, very pleased on my 1HD-T DI diesel Toyota engine .. which it's old school turbo diesel ..
Reviewed by Hank:
Great oil use it always
Reviewed by Diesel Daryl:
2005 Dodge 3500 5.9 Cummins. 222391 miles only oil used since first oil change. I pull 12000 lbs. trailer everywhere .
Reviewed by RAT454:
Have 346000 on my 03 Dodge Ram Cummins. all ever ran in it.
Reviewed by Joe:
Best oil ever,I'm very happy with the product
Reviewed by Genny man:
I've been using this oil.for approximately 15 years in my 17 yr old truck.The oil is still gold in colour after three thousand miles
Reviewed by Jerry from Madera:
I use Amsoil engine lubricants and other products in all my vehicles. The Ford diesel has been a real workhorse, taking me on numerous trips ranging from literally the equivalent distance from Paris France to Moscow Russia and back! Plus along desert trails that had my buddy grabbing the
dash and asking "THIS is the road!"
Amsoil heavy duty diesel & marine oil "had my back" on such trips.
Reviewed by Dr. Bill:
Hard to leave a review on something you can't see working. But been using it in my diesel truck for 10yrs. If anything, shipping could be a little less but the product is great.
Reviewed by Twilson:
I recently switched my old chevy 2500hd duramax diesel to Amsoil's heavy duty diesel and marine 15w 40 synthetic diesel engine oil. I switched to Amsoil mainly because I heard in my years of being a diesel technician that amsoil has made an outstanding product. So I decided to run it in my pickup. I ran it for 1 oil change of 5,000 miles which I know is way less than the 25k they recommend but I was skeptical of a 25k mile oil change on a 250k mile farm truck. So I dropped the oil a 5k and sent in a sample and I got my results back saying that my pickup is in like new condition and that i was wasting my money changing my oil too often. They said the amsoil additives we're among the beet in any synthetic oil and my pickup was running clean with almost no soot in the oil. So I would recommend amsoil to any potential customer that just needs the nudge to try it. Don't worry because you won't regret it.
Reviewed by Mr. Wilson:
I have two Ford F-250 trucks, a 1999 and 2000. Both have 7.3 Diesel engines. Using EA extended life oil filters along with this oil, I change the oil once a year and the oil looks like the day I first changed it. It is the BEST oil I have ever used. I now use AMSOIL products in all my equipment.
Reviewed by Frenchy:
This oil addresses one of big rig o/o life's saddest complexities (break downs) with such sweet simplicity. ..
Extended oil change (cat 3406E) thus cheaper even in short term (I do 45k between oil changes )do the math !! 1.9 million miles later and running strong and fast...
Reviewed by Michael William:
After installing the Heavy-Duty Diesel & Marine Motor Oil SAE 15W-40 (AME) in our 2006 international trailer we have extended drain intervals by more than 3 times with the help of periodic used oil analysis.
Each time the report comes back recommending for continued use. At this drain interval, it costs less than half regular oil.
Also our logs shows 8% lower fuel consumption for the same distance compared to regular oil, so this actually puts money back into our business in fuel savings.
Canada
United States
I have and will continue to buy this product.
I have been using 15W-40 Heavy-Duty Diesel Oil in my 2004 F-350 Diesel truck for the last several years. I also use Amsoil filters. I change both once a year and everything is fine with my truck. The ordering and delivery cannot be any easier. The price and advantage of only needed to do both once a year cannot be underestimated.