This oil seems to hold up very well, the viscosity is excellent. This is the only oil I've ever used that seems to hold up better than the rest I've tried in my class 8 truck.

Great oil for the Cummins

Really like the product and will keep using from now on and will use other products in the future

This is the besr stuff you can use. Can't beat the price hello

I experimented amsoil a few years ago, Then more technology came aboard , with synthetic....oils for everything.... With vehicles selling for $ 1,000,000 , even parts.... With your help parts last longer.... Thank You...

High product quality aside, I always appreciate the service and how fast and reliable it is. Where I'm at i can have anything from Amsoil second business day on my doorstep. Free shipping

Great products but customer service not so much

I have been using Amsoil products 20 years. I have not found a better product for all my vehicles.

Nice and easy to order good product no problems on my orders before tanks por your service

My first order was the hole oil change kit with filter for my 2021 GMC 2500 AT4. The oil is great but the only thing that I really disliked, is the I was sent the wrong oil filter. So I had to go buy a different one right after I started the oil change. That was very frustrating, and disappointing. But otherwise a good product, I won’t be buying the whole kit again.

Use this in an 02 Duramax, has a sticks well to metal surfaces.

It's very oily, and quite slippery. Seems to lack all stickiness or roughness.

Good oil i change it out at 5k

Great stuff

I have been using this in my 6.7 Cummins and my farm tractor since 2015 and wouldn’t use anything else. Great product

This is great oil. Just traded in my 2019 mack and the guy that appraised my trade in said he has never seen a engine with 800,000 miles on it that clean inside. I do 60,000 mile oil changes and have never seen the oil look stressed.

Best oil on the market.

I really do swear by amsoil, their fluids hold up and definitely are worth it. Id run mobil delvac in my LBZ Duramax for many years but it just seemed like itd never hold up like it should and would seem to burn off. I tries amsoil and never looked back. Whenever its time to change my oil, not only does it still have great lubricity, I drain out the same amount that I put in and it holds up even if I’m busy and cant change it immediately. It also makes my engine run a lot more quiet. I definitely recommend this stuff, if you love your truck or machine, you want to make sure its well lubricated so its not wearing excessively and will be around beyond its potential. Give er the good stuff, Amsoil is that good stuff!

I have used 15-40 in my Chevy Duramax since I bought it, quieted it down, lowered temps and overall exceeded my expectations!

Great company great product speedy delivery made in the USA!