Customer Ratings & Reviews

I used royal purple for at least 2-3 years. My duramax literally ate at least 1-2 quarts a month. I switched to amsoil and used the same oil for almost two years and only had to add 1-2 quarts the whole time.

Used Amsoil for years. Always satisfied with product and service.

I have been using Amsoil for several years now. It consistently out performs other synthetic oils.

I installed the oil bypass kit one year ago and have only run Amsoil 15W40 Diesel through my engine. I wanted to test it out and find out how well this oil would perform and I was not disappointed. With 1 year and approx 25k miles on the oil, several long distance hauls with trailers between NC and TX, and AL and TX; I never felt like the Amsoil would leave me stranded. I have 100% confidence in the oil and all the Amsoil products.

Great oil! Really efficient and truck is running smoother.

Great stuff! Quiet operation. Its a great piece of mind using quality products. Amsoil needs to keep sending stickers!! Haven't been getting them lately with my orders...

Engine seems like it better than whatever was in it before. Dropped my oil pressure a little bit, but it was my first oil change after buying truck used so I don’t know what was in it before. I’ll continue using Amsoil products for the life of my diesel.

I’ve been using Amsoil in all my trucks for 12 years Awesome Products and very Fast Service

I want to start by saying the customer service was very excellent they knew everything about the product I was ordering!!! and very swift shipping I had my oil in two days unbelievable thank you !!!! I would love to write a review on how the oil 15 W 40 max duty signature series full synthetic is holding up in my new high-performance 6.7 L diesel is performing !!!!!but of course with the hard freeze and pandemic my mechanic is very busy ,as soon as my old motor is Pulled out and my new high-performance motor in.. I have a 800 mile break in. After that I will have the oil tested !!! and right another review !!!15 W 40 synthetic Max duty signature series. Thank y’all at AMSOIL. Look forward to yawls business for many years. Please pay no mind to the 5 Star rating it will not let me post unless I rate it I know for a fact that it is a very good oil I have not run it yet Or tested it in my new high-performance motor!!! Like I said earlier in my review I will write another after I hit run and tested it

I run this in my 97 Dodge 12 valve Cummins 190K and it runs smooth as silk , hauled a 33'camper from Little Rock to Grand Junction ,CO Feb 2020 and it purred right through the Rockies zero problems . I suggest it to everyone I can .

Great oil for all weather applications

Reviewed the test results and I am satisfied the oil suits my needs. I do some heavy hauling and have used the oil since the truck was new. No issues.

Love amsoil the only oil I run in my diesel truck

I was running another big name brand (T6) synthetic oil before, after switching to AMS oil I can here a difference in how the motor idles. Much smoother and quieter than before

Not much to say other then best oil on the market. I don’t use anything else. I use this in my 2001 Chevy Duramax that is always towing. 10/10 recommend

GREAT PRODUCT BEEN USING FOR YEARS WITH NO ISSUES, CUSTOMER SERVICE ALSO RECEPTIVE TO REQUESTS. I FEEL LIKE I KNOW THEM PERSONALLY