Have run this in my 5.9 Cummings since new (22 yrs), 160 K and going strong.

I have been using Amsoil products in all my vehicles for almost 20yrs ( diesel truck, harleys, hot rods) without a single oil issue. I recommend these products to everyone.

I’ve owned my 1998.5 Dodge Ram 3500 Dually since 2000 and, although I tried Kendall Super D3 in the beginning, I wasn’t quite pleased with it and the availability of it. So I changed to Amsoil and I have never looked back. I now have 366,000miles on my truck and it still runs smooth as silk with no engine problems whatsoever. I also run Amsoil gear oil in the front end, reared, transmission, and transfer case. I change the oil on an extended mileage plan in conjunction with my mechanic and I simply could NOT be more happy with this product. Combined with an Amsoil Bypass filter system my truck will very probably outlast me!!!

I have used this oil for many years. Changing once a year, approximately 12,000 miles. My truck continues to run like new with 257000 miles on the clock

It use to cost me about the same for 3 gallon oil change as I paid for a five quart one, not so nowadays

just had the valve cover off my Cummins Marine 5.9. pristine at 1000 hours. Amsoil products are the only oils in all my power equipment.

So far so good Time will tell

Been using this oil since first oil change.

The AMSOIL for my diesel is AMAZING. I would never use anything else. Thank You for such a GREAT Product :-) God Bless Bob

Love many different Amsoil products. Diesel engine oil works great in my Tractor

I've been using Amsoil Synthetic Oil for many years and my diesel engines just keeps lasting.

AMSOIL products are always reliable and ship quickly. Packaging is durable and clean. They've even sent me free bottles of firearm cleaner in which worked so well I purchased them on top of my usual oil orders.

Always use this in every diesel rig. Some now as old as 25 yrs. Never an oil problem. On the road at all times and never down due to oil. Don't use this at your own peril. Peace of mind is crucial.

Love this product great price to. Going to switch all my vehicles over to amzoil.

Fast shipping high quality product

Fast shipping great quality!

Fast shipping great product

I have used this oil for many, many years in my 1985 Mercedes Benz 300SD Turbo Diesel and my 1951 John Deere Model R diesel tractor engine with excellent results. Zero failures

This is the best oil for my 2004 John Deere X495 diesel tractor, the pony motor on my 1951 John Deere Model R diesel tractor and all my smaller 4 cycle gasoline engines. Been using it in these applications for years and years with excellent results and zero engine failures.

This oil seems to break down at approximately 125 hours. The oil turned black and got really thin. This caused my oil pressure to drop 7-10 lbs. I’m going to give it one more try before I witch brands. This oil is being used in a Cummins 5.9QSB that is in my boat and they recommend 250 hour oil changes. This oil will never make it that long. Thank you for your time.