Customer Ratings & Reviews

On my last oil change, I switched to the 15W-40 Signature series Max-Duty synthetic Diesel oil. I had been running the 15W-40 Heavy duty Diesel and Marine oil since 2008 with excellent results, so when this one came out I figured why not give it a try. So far, the oil has performed exceedingly well. Engine runs cool, smooth and quiet. I own a 2006 Silverado 2500HD LBZ Duramax which is aproaching 400,000 miles and it's still running great. Oil change intervals have averaged between 12000 - 18000 miles for the life of the truck. I still don't even need to add any oil between changes. I run Amsoil lubricants throughout the whole truck.

Been running this oil for 50,xxx miles + and zero issues.

It is the best oil for the price.

I have used Amsoil in all my vehicles for 25+ years now. You simply can not get better oil.

Use amsoil in all three of my vehicles.

I like this oil it is great!

Great oil !!!! Lower evaporation than all others I've tried

I have run your oil and your bypass filter system over 200,000 miles while towing a 10,000 pound travel trailer most of those miles. I have had zero problems during that time. I change the oil one time per year, the bypass filter one time per year, and the full flow filter two times per year, while putting about 20,000 to 25,000 miles on the truck. This takes all the hassle out of oil changing, and no problems. I had the oil analyzed for 5 years, and never received a result that indicated the oil needed changing at the end of the year.

I change my oil every 8 to 10 thousand miles with a 2 quart micron bypass filter. I added myself very easy with kit 215000 miles and never lost a fuel injector, of course bullet-proofed it no problems love it

this is a superior oil to other diesel oils but at least on a 5.9l cummins the oil gets way to thick from the soot at around 5000 miles, I would not recommend going past that interval, I am using the amsoil filter as well. My 7.3 power stroke takes 15W40 and goes 20k miles before getting that bad. This oil doesn't stand up to the amount of soot produced in 5.9 cummins in my experience which is why I give it 4 stars

Great product.! Amsoil saves me money.! I get many miles before oil changes. This product will extend the life of my vehicles.!

I rely on the product being able to go the distance or time frame without worrying about going a little longer because of not having the time to change it . I have total trust in the product. I have had better mileage results with this oil also.

smooth running .

I have used AMSOIL products for 30 plus years. That should say how I like their products

Love the product. No complaints

The knowledge that you've used the best product for the job equals many happy, trouble free miles.

Very pleased with the Amsoil product line. Great performance and this oil is quite honestly the best for my diesel equipment

Good oil

I use Amsoil in all my equipment (several are diesel powered), I'm very happy with their product and I've used it for years.

If you have a powerstroke diesel (any year) you need to run Amsoil oil along with the oil bypass system. My results from Blackstone Labs have been outstanding. We pull a 5th wheel camper and because of the heavy work that the truck does - we change our oil every 7,500 miles / 200 hours.