Customer Ratings & Reviews

I run this in my 7.3 powerstroke for 10k miles and change the oil filter halfway. So far no issues after 130k

Use in my Freightliner with bypass and powerstroke with bypass. Analysis done every 15000 miles on both. Very low wear metals, soot and oxidation out to 60000 miles on Freightliner.

The best!

Very happy with the product. Have always heard great things about amsoil. And now I'm a believer.

I’ve used this oil in several different diesels I own and feel it definitely stands out from the rest in the synthetic oil market. The lubricity and thermal breakdown resistance is unparalleled by any of its competitors. I’ve noticed a reduction of value train noise and smoother and easier startups. Superior in quality, highly recommended.

Very good products and services.

Truck runs smooth. Couldn’t be happier.

I use my diesel 3/4 ton gmc pick-up to tow a 8000 lb. Travel trailer in northwest mountains. Never once did I worry about the extreme environment I was in

All Amsoil products blow away the competition. It is just a great product. I use the signature series in my diesel truck and change the oil at 15,000 miles. It just runs better. I have I have 254,000 miles on my Chevy 2500 HD diesel.

Best products on the market!

Great heavy duty oil have to order extra or remember to order in advance i dont have any off the shelf dealers local

Best oil that I’ve used on any of my vehicles!!!!

My diesel Duramax Chevy is towing heavy loads. I need the best oil, this would be the one! Engines are so expensive, don't skimp, protect your investment.

I own a 2004 Ford F250 with a 6.0 Powerstroke diesel engine. I am still running the factory injectors and high pressure oil pump at 200k miles. This is virtually unheard of; not if you're running Amsoil!

Engine noise has reduced, better startups. Truck feels a lot smoother. First time using this oil already impressed. 02 duramax

This is the best oil I have ever gotten. I feel like I'm spoiling my truck.

Great product.

I found my Ram Cummins runs cooler turbo Temps under a heavy towing using the Amsoil 5w40 synthetic by 100 to 150 degrees! Great product.

Purchase it cause I heard really good about it so I tried it. I have to say my 2013 duramax 6.6 sure loves it !!! No more clunking, or rough starts. Really impressed. Not ever going back to Rotella!!