Customer Ratings & Reviews

I've been using AMS 15w-40 and the 25000mile filter for over 170,000 miles and have been completely satisfied.The fact that I don't have to take the time to get an oil change every 3000 to 5000 miles helps a guy like me who's on call 24/7.

I have been using amsoil in my truck form the day I got it about 5 years ago, Chevy silverado 2500hd Duramax and I have to change my injectors out at 169000 miles the inside of my engine was so clean you could have ate off it. I now have 240000 miles on the truck and drive it as a daily driver over a 100 miles a day. And still use amsoil

I use The 15-40W in my 2014 Ram 3500 with a Cummins 6.7 diesel engine. I pull a cargo trailer daily for my construction business and also have a 40 foot 5th wheel trailer that I am on the road with 45 - 60 days a year. I never have to worry if the engine is being well lubricated.

This product ROCKS! Have used it in my diesel truck since my first oil change in 2006. My truck has 170,000 miles and still runs like a top and still pulls my 5th wheel all over the USA. Also use an Amsoil oil filter and together they are the best in my humble opinion.

I began using AMSOIL 15w-40 Synthetic Diesel oil 3 years ago. I can tell a definite difference in the performance of the truck & there has been increased fuel mileage with & without towing my 5th-wheel. I also have extended the interval of oil changes to 15,000 to 18,000 miles. Based on my positive results with this product I also had my transmission fluid changed to Amsoil.

I Can always count on great quality and fast shipments from Amsoil. I have only used there product on my 2007 GMC Diesel truck from the day I purchased it brand new.

Have used AMS Oil for years and it has performed as advertised. Was always a little tough to find a salesperson close to home now it is very simple to order and delivery was fast.

I switched from the standard Rotella 15W-40 about 1.5 years ago to the Amsoil 15W-40, and was the best thing I could have done! Though some of the new diesels are rated for 7500 mile oil changes, when using Rotella I still changed it every 3k miles. With the new emissions on these trucks, the regular oil doesn't last near as long. After only 3k miles, the oil was almost as thin as water, and the lubricity was nearly gone. After switching to Amsoil, I can go the full 7500 miles and then some (with oil analysis), and the oil still feels like new. I have since started using Amsoil to replace all the fluids in my truck.

Our duramax is a daily driver along with pulling a 43 ft toy hauler. I will be purchasing other products also.

I have used this product for many years and I have had great results. I am glade I came across amsoil the product has saved me alot of money.

I have been using Amsoil in my diesel towing vehicles sense 2004, when I purchased my first diesel GMC 2500 pickup. I tow a 10,000 pound Airstream Travel Trailer 10,000 to 15,000 miles a year, and change my oil one time each year. I have used an Amsoil Duai Filter System with the Bypass filter. I change the Full Flow Filter two times per year, and the Bypass filter one time. I got my oil analyzed each year just before my oil change for six years. I never had the lab recommend I change the oil. I put 125,000 miles om my first Amsoil truck, then sold it to a friend in 2014. The oil I am reviewing was bought for that friend, that is stil towing a Travel Trailer and changing the oil like I did. I now have a 2015 Chevy 3500 Diesel set up just like my 2004 GMC was for Amsoil and dual filters. The order for this oil also included the oil and filters for my new truck. I look forward to getting the same results with this truck doing the same job.

I have been using Amsoil for many years I use nothing but Amsoil in my vehicles I have a Duramax diesel 6.6 2011 In my opinion Amsoil is the best synthetic oil on the market .

Duramax 6.6 runs quiet excellent feul mileage

Did an oil change and filter and first week I notice that the engine had smoothed out , and my mileage went from 11.3 liters per 100 k down to 10.6, that's just in 22 kilometer ride to work .Can't wait for a highway run coming in September.

have always used Amsoil had my order within a couple days very fast

Been using the oil since the vehicle had reached 25000 miles. Now it has just short of 120,000 miles. The oil lasts one year. I notice no oil comsumsion between oil changes. Use the truck to pull trailers beside just normal driving. Also belive that the oil aids in cold starts during the winter months. Starting in sub zero weather has not been an issue as todate.

I use Amsoil in my 2015 F-250. This oil holds up under the stresses that come with running 11 hrs. a day 5 days a week in commercial use. My 2015 already has 155k miles on it thanks to Amsoil, without any engine problems. I have tried other oils, even Royal Purple Duralec, but none compare to the 15-40's strengths when under the high temperatures of Summer in the south and the cold temperatures of the north in Winter.

My brother has owned an F250 Diesel for over 10 years. He told me that his truck performs the same as it did 10 years ago and he has had no fuel injector or motor problems. His friends have had those kinds of problems with their trucks. The difference he said is that he has been using AMSoil in this engine and transmission, and his friends did not. So when I bought my GMC 2500HD Diesel, I bought AMSoil for my truck. Their record is impressive. If I can trust my brother, who can I trust?