Customer Ratings & Reviews

New customer and just started using Upper Cylinder Lube. In new truck, sounded better on first tank. Will know about gas milage in a few days when we take a highway trip. Gave one to my brother-in-law and he said his computer was saying 5 mpg increase on 2.7 L Ford truck with over 200,000 miles. Gas milage said 30 mpg.

This product is outstanding. I put in a small container every 3,000 with a fill up to keep all the moving parts in the engine clean and doing their job. I find the gas mileage improves. It is vital to deal with cheap gas as well. I try to select the station with the superior gas but it is becoming more of a challenge. The additive compensates for the inferior gas and is a must to keep the engine clean.

Awesome product really helps your gas and fuel system stay clean and running smoothly highly recommend try it and see the difference in your vehicle

Use every 5000 miles, great product

This fuel additive works great and I use it every oil change to keep my engine clean and boost my car's performance.

Great product to keep my engine clean, and slow down deposits.

Great product

I notice that I got better performance. Better throttle response and more power!

Just recently bought a 99 WS6 Transam that had been sitting for a few years and It had a rough idle at times. After using 1 bottle of this I could definitely tell a difference. The idle is much smoother. I am going to use 1 more bottle then start following the recommended time. Another great Amsoil product.

Amazing I used in all my 3 cars …. Love it

I love this stuff, my engine idles smoother and got 3 more miles to a gallon, love it.

I add this to the tank at filling and after couples Miles I can notice the change in quick shift response

Superior product I use it regularly and even send it to my daughter in Denver Colo. who loves it too . My son in Oklahoma uses it too . We are Amzoil believers and users !

Good

I run this product every 4 to 5 thousand miles, it helps optimize my MPG and keeps my emission equipment happy.

Ron and 2019 mustang GT every 4000 miles keeps it running at its best good stuff

Tremendous product. Keeps fuel systems clean and contributes to increased MPG. Engine idle is always smooth and no hesitation on acceleration.

I noticed an increase in gas mileage and a better response when I stepped on the gas right away. This product does what it says it will do.

Hello, recently purchased some Amsoil PI performance improver and I'm very happy with the results of this product. I feel that it did a very good job in cleaning the fuel system and taking out any contaminants that were remaining in there. I noticed acceleration was better overall and very smooth shifting. I like how it is engineered to be used every 4,000 miles so it's not something you need to worry about putting in your tank every time you fill up. I would not hesitate to purchase this product again I feel it's a good buy and a good value.

Best additive ive ever used. Can actually feel the difference in performance