Customer Ratings & Reviews

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.

I am a long time customer with AMS oil, and highly recommend this product to everybody ,

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!

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.

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

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.

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.

2005 Dodge 3500 5.9 Cummins. 222391 miles only oil used since first oil change. I pull 12000 lbs. trailer everywhere .

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

Great oil use it always

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

Cheaper and holds up better than royal purple

Recently purchased 4 gallons for my 7.3 powerstroke & join the preferred customer program, couldn't be happier with my choice.

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.

I'm using this one, very pleased on my 1HD-T DI diesel Toyota engine .. which it's old school turbo diesel ..

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.

Have 346000 on my 03 Dodge Ram Cummins. all ever ran in it.

Best oil ever,I'm very happy with the product

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.