Customer Ratings & Reviews

I have four dodge diesels and a cat powered welding machine and I run this oil year round with zero issues. I do oil changes every 25000kms.

I use this oil in my 2014 Dodge Ram EcoDiesel. Amsoil updated the oil from 5W-40 to 10W-40 based on Dodge recommendations. Great oil.

Under heavy usage and need peace of mind

Use this oil in a tow vehicle never loses a drop of oil in 5000 miles

Although I've never use this oil before I'm confident I'll love it as I've been useing it in my M/c for years ! You just can't go wrong with amsoil!

My engine is still running and since I can't see inside it, it must be working.

It kept the engine cool. It doesn't break down.

My mileage increased a bit. The engine runs a lot smother. I plan on keeping my truck for many years and this oil is go to oil.

Dumped class 3 synthetic rosella t6 for a true synthetic class 4 PAO Amsoil Sig Series 5w-40. Turbo Diesel is running smoother, quieter, cooler and 2-3 mpg boost! Worth the money!

I was a Royal Purple junkie since it was the only synthetic available to me where I live and got it free. It worked great in my gas truck and other gas vehicles. I switched to Amsoil since I purchased a diesel truck and became a Preferred Customer. Really like that part !!! The truck runs much better and accelerates better than the Ford oils that were in it and oil change at 25,000 miles is a nice $$ saving feature. I will switch to the new synthetic 5-40 on the next oil change and then extended changes past 25,000 would be nice. I monitor all things done to my truck and log it. Put 9,000 mikes on the truck in less than 4 months and excellent results !!!

Best lube oil for my one ton Ram 3500. But not without the Amsoil EA filter.

I use 15 40 in any vehicle I have which includes my tractors, lawn mowers.

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