Customer Ratings & Reviews

I've been using signature series in all my cars and motorcycles since 1980. I've keep them and put high milage on all. I'm 72 years old and maintain my cars and motorcycles always with Amsoil signature series products exclusively. Never a lubrication issue. Parts last and last. Thanks Amsoil

I was a long-time Mobil 1 user. But now that I am retired and I have the time to change my own oil again, I started reading more about the differences in synthetic oils. I always thought Mobil 1 and the other major brand "full synthetic" oils were just that - fully synthetic. When I learned their base oils are not 100 percent synthetic, and the only fully synthetic oils were AMSOil, Royal Purple and RedLine (there may be others), I started looking into test results that are all over the internet. For my money, AMSOil came out on top for the driving I do. All the tests indicated it had the lowest level of thermal breakdown of any of the synthetics, and one of the best additive packages. The fact that I don't run it for 10,000 miles - I change oil every 5,000 - gives me the confidence that my engine is better protected than with any of the other major brand oils. I know it costs more, but to me the peace of mind is well worth a few extra bucks. It is a great product.

This is by far the best Synthetic Engine Oil I have ever used and I will continue to use it in the future.

While I change my oil more frequently than recommended by AMSOIL. I have had no issues. 97,000 miles and get same fuel economy. Used oil is black but not metal on the magnet.

It’s nice to not have to change your oil 5-6 times a year

Been running Amsoil 5w-30 Signature Series Engine oil since 800 miles on my new truck 👍 Along with Amsoil EAO17-Oil Filter And Couldn’t be happier with the Protection Amsoil Provides !

Love Amsoil products they’re so worth it keeping our vehicles running well!

I have been using AMSOIL Signature Series 5-30 wt oil since my 2012 Subaru Outback was new (changed oil that came with car at 1000 miles). I always change my own oil and filter (AMSOIL) and now have 259,312 miles on the car. I have never touched the engine except to have spark plugs replaced every 50,000 miles or so. I also use AMSOIL Transmission Fluid without transmission problems. I trust the AMSOIL products to be the absolute best available.

simple, easy, efficient timely delivery as always

Upgrading to AMSOIL and the higher viscosity has made a major improvement in performance and making the engine perform more quietly. Ordering was easy and delivery was faster than estimated.

Knowing that I have amzoil in my engine crank case give me a piece of mine

There's not an oil that can beat Amsoil

Holds up better than any synthetic oil ive used so far. Fast and convenient shipping as well!

This 5W-30 weight oil is probably the best I ever used in. My car runs very good on it. I also buy the upper cylinder cleaner for the gas.

This stuff is the best stuff on the market.

I'm on my 3rd oil change with the Signature Series. After 5000 miles, you can still see through it. My oil pressure is up and my oil temp is down. I'll never use anything else.

Do you make oil for lawnmowers?

engine sounds and runs good

I use this oil on all my 3 vehicles. It has reduced Engine Noise and works very well.

I trust my vehicles to Amsoil always, don't be fooled by cheaper synthetic oils.