Customer Ratings & Reviews

This stuff is awesome, been using every tank of gas.

I use Amsoil Upper Cylinder Lubricant in my Direct Injected Subaru Crosstrek as well as my Mitsubishi Mirage and 3/4 ton Chevrolet (which don't have direct injection). It seems to be doing a good job of keeping my fuel injectors clean/ engines running efficiently. **I find that their Upper Cylinder Lubricant provides good protection between treatments using Amsoil PI. Upkeep is key and so I've been using this on my vehicles since they were new. Idling and throttle response are good with all engines.

Worked as expected from a Great Company!!

I use this with every oil change along with the performance improver and use the engine flush about every third oil change engine always is clean and never Burns any oil that's saying a lot for a Subaru

A good in between treatment after using the P I improver

I use this product in everything that has an engine. Side by side, truck, car, generator and snow blower.

With a recent tuneup and cylinder exam it was obvious even with 120,000 miles . The cylinder area was cleaner now than it was at 70,000 miles another winner from Amsoil !

first time i used this product so the jury is still out

I use it in my duramax. It has 275k all original.

Great stuff it Amsoil! highly recommend

AMSoil “UCL” makes them purrr. No more sounds. Buy a case. This stuff is awesome.

great product for fuel treatment and cleaning.

Best

Great product for any engine!

I'm taking their word that it works but really don't have a clue if it really does anything or not.

Not sure if this is a high octane product, the car feels faster when used, and back to normal after a tank of gas. Feels the engine is running smoother.

I have been using Upper Cylinder Lubricant for two GM 2.4L GDI Engines with great results. One engine is approaching 120K miles, the other 100K miles. Neither has had issues with injectors or carbon deposits that typically build up on pistons and affect low tension piston rings.

I love all Amsoil products, they're high quality products, I've been using for 20 years now, my cars are lasting forever. Thank you Amsoil.

I started using this on my new 2021 Gladiator once per month but couldn’t really notice anything. After about a year, I upped my usage to every fill up. Still didn’t notice much of anything. Discussed with my gearhead mechanic buddy and he said it was probably overkill but couldn’t hurt as long as I wasn’t using low quality gas. So I stopped using it for some months and that is when I noticed that the engine just seemed to run rougher or not as smoothly. I decided to restart using the stuff and almost immediately noticed the smoothness return. It’s definitely doing something and I’m not having to skip meals to pay for it so I will continue to use it at every fill up.

We like the product and use it at every fill-up. The one downside is the foil seal is hard to remove, with no pull tab.