Only oil I use for my F250.

Have a 2009 duramax 364,000 miles runs like a champ. Would not use any other oil in it.

Have a 2001, dodge ram 2500 with a Cummins diesel and automatic transmission. I’ve been using this oil since I bought the truck in 2004 and have had zero oil related issues, and this truck is regularly, overloaded and overworked.

Amsoil is the best oil on market! Have had it tested after using and viscosity stands true! Only oil I use in all my motors and engines

This oil out performs the Ram suggested oil for the ecodiesel and the 2.5 gallon jug is the perfect size. Couple the oil with wax filter and it is a winning combination.

Great product been using amsoil for years now.

I've run this oil and Royal Purple synthetic 15w40. I do find Amsoil quietens my older deisel down better.

I have been running this oil since I bought the truck new. I only trust Amsoil in my truck.

Been using Amsoil’s 15w-40 on my Duramax for years and I absolutely love it. I can get 15-18k intervals out of it and it’s still got a couple thousand more miles left in it. Take care of your vehicle and it’ll take care of you… run amsoil

Great product with super fast shipping! If you have a tech question they are quick to respond to your email.

Have used Amsoil Diesel Oil in My 2005 F250 for 190,000 miles i would not use any thing else.

This is the first time I have used the signature series oil I always used the silver jug previously. I rate this oil so highly due to the instant noticeable increase in fuel economy after my most recent oil change. The big diesel runs at lower RPMs during all driving ranges and I have gained approximately 2mpg!

Love it

I've been using Amsoil in my 6.0 Powerstroke for almost two decades now highest quality oils available that's why I use it and that's why I recommend it

Great product have been using it for several years

Best oil I have ever had!

I have been using this oil in my long distance trucks for years. Cummins and Caterpillars Oil performance is what i hold in high regard and this has never disappointed me.

Only use amsoil I. My cars and truck. Won’t allow anything else in my motors

Awesome oil for my lb7 Duramax it has 306,221 miles on it and still running like new, iv never had any issues with Amsoil, I highly recommend it for any Duramax

I've been using Amsoil Signature 5W-40 Diesel Oil in my 2015 Ram 1500 EcoDiesel since it was almost new. I'm confident that using this oil has helped keep my rig going strong without issue for the 240,000km's that are on it so far.