This is probably the best in the world.

I work my Diesel hard towing doubles in the mountains you can always count on Amsoil to protect your engine

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

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.

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.

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

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

The absolute best for my 2002 7.3L Diesel Excursion.

Great oil, I use it in my 2006 Century Freightliner, I have over a million miles on it. Wouldn't trust any other oil.

I have a Chevy Silverado 3500 year 2008 410,000 miles on the truck love this product

Over 200,000 miles on F-150 using this oil no issues what so ever with engine.

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.

I recommend AmsOil products all the time to friends and family. Well worth the investment.

it's a good product but I don't like the gallon jug design. They're hard to pour.

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.

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

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