Customer Ratings & Reviews

I drive a lot of miles in a short period of time and I don't have time to change oil every 5 to 6ooo miles

Perfect product

I've been using AMSOIL heavy duty diesel oil for years and it has performed extremely well. This year I decided to try the Signature Series Max-Duty and was I amazed. I didn't believe I could tell the difference but the engine runs even smoother. I tow trailers with my truck and protecting the engine is paramount to reduce wear and lengthen the life and this oil delivers.

For my Duramax diesel

You can't go wrong with the best of oil produced on the planet Peace of mind means everything and Amsoil gives you that peace of mind

I use this oil in my skid loaders as well as heavy duty pickups pulling heavy loads daily. I have been sold for many years after I had 6.0 diesel that dumped all the oil and the only thing that saved the motor was this product. All the shop had to replace was head gaskets

Use this in my 2015 super duty 1 ton dully. A do a lot of heavy towing long distances

In my Excursion Diesel 250,000 miles

First, I'll say that I love Amsoil. I run Amsoil in every engine/transmission/differential/etc I own. I'm not sure about this new oil. My oil temp in a Ford 6.7 Powerstroke usually runs about 203 degrees (previous version of Amsoil diesel oil). With this new oil (December it might have come out???) I'm running 7-10 degrees hotter on average. I'll probably try one more oil change with it and if it still runs hotter, I'll have to find another brand.

I am astonished at the engine oil life provided by this oil, compared to the Mobil synthetic I used previously. I'm at 14000 km, 80% city, and the computer is telling me I still have 20% oil life. Previously I would get to about 10k and be looking to change. Admittedly I changed to Wix filter at the same time from Oem, so not a 100 % true comparison. Winter, with more idling, will be the real test. Engine seems to be running cooler even in 30C weather- that's hot for us!

I have a 2011 Chevy one ton dually long bed . Now over 100,000 miles and is running great I feel because I have used Amsoil since day one . I have used every brand with prior vehicles and always go back to Amsoil.

Use it a 09 Chevy Duramax, starts great even if it hits 0 or below

Buy diesel, gas oil plus PI for my gas vehicles. Amsoils is the best!

I currently use this product on my 2016 Ram EcoDiesel with no issues and have use the previous 5W40 diesel product on previous diesel pick up trucks and heavy-duty equipment with no complaints. Thank you Amsoil.

I'm running the 15w-40 Amsoil Signature Diesel in my Corvair air cooled engine in my 22 foot RV. Very heavy duty use for a 3 liter engine from the '60's, and it performs perfectly, along with the Amsoil 75w90 Severe Gear in my differential, and Amsoil ATF in my Powerglide transmission. I use nothing but Amsoil products in my 17 Prius, the 16 Subaru Forester Turbo, And every car I have owned in the last 15 years, and will continue to do so.

I like to take extra care of cars that I love. For those cars, I only use Amsoil products. Why? I trust and appreciate the information and research they provide. I'll pay extra for that trust.

Best oil out there. Installed a bypass filter system as well. Very happy with all aspects. Installation was simple

Yearly oil changes, how good is that!

Engine ,primary and transmission fluid for my fxstdi.

I have been using Amsoil for many years. Amsoil is the only product I put in my machines! If you don't have time or inclination to change your own oil, buy and take it to whoever does your oil changes you will still safe money and your vehicle will love you.