Customer Ratings & Reviews

We have a 2013 Mercedes S550. My normal highway mileage from Sacramento CA down I-5 to Orange County with the Cruise set at 75mph normally gets me a squeek under 27MPG. I though I would try some of this Upper Cylinder Lubricant on our trip to Wichita KS going the upper route of I-80 then down to Denver and across on I-70 to Wichita. This time with the cruise set at the speed limit indicated (70-75 or-80), I was enjoyably surprised to consistently be coming in at 28.5+ mpg per tankful- both East as well as West bound on the same route. When I got home, I ordered 2 more cases right away and have been using it most every tankful now.

Bought a case about 2 months ago, I fill up once a week, the engine has been smoother and definitely more power and better performance, being consistent on using it for every fill up makes the biggest difference. I’m now on 5th fill up using one per fill up and stayed back to back consistent using it and love the performance in my Lexus is250

I can feel the pickup or snappy response. This is the best.

Awesome product

I very much recommend AMSOIL products.

You will feel the added power in the engine when this product starts cleaning and lubing the upper portions of it.

A must have now a days in 2022 with the so such bad gas around having atleast fifteen plus percent ethanol in it.

I think my engine is just a bit quieter when idling when I use this product.

I began using Amsoil Upper Cylinder Additive after I had an Amsoil oil change done to 2019 Lincoln MKC 2.0T. I don't really know by seeing that it works but by feeling the performance. I am very confident in it's conditioning regarding the upper cylinder, the turbo and all the components that have a say about how the vehicle will run. We just bought a 22 Hyundai Santa Cruz Limited 2.5T and I will add the product to my first fill up. Do yourself and your second best friend ( married know it's the spouses ) your car; whatever his or her names they may be; a lifeline such as Amsoil products. Also as a tip go to You Tube for the Amsoil vs Major name oil comparison testing I was amazed!

Will buy again

This additive works great cleaning & lubricating the intake valves

Removes knocks

I notice at least 1 to 2 miles better per gallon when I add this to a tank of fuel truck runs great only use regular fuel no pain no hesitation works as advertised

I believe in UCL. When you think about highly-humified air sitting in the upper cylinder, cooling, and water condensation, UCL totally makes sense. Add to that keeping the valves clean and better gas mileage. Maybe why my Hemi has 71K and runs like day 1 with zero smoke?? I'm convinced. The bad part is the awful seal, hence the 4 stars. Why not a pull tab like was on these bottles for a short while...like every other sealed bottle in the world??

Great results.

Seems to work great! I use it every tank. Then once or twice a year I use P.I. on one tank keep everything clean.

My engine would sometimes tick at startup and occasionally even a small puff of smoke from exhaust. I now use upper cylinder Lubricant at every fill up and have noticed no smoke or ticking on startup. Good stuff! My research online seems to be that without zinc in todays fuels that the cam lobes wear after while and is not a reversible situation. I am on my third case and seems to be satisfactory results so far.

2016 f150. Truck runs smooth. Amsoil just make the best. All I can ask is that my truck keeps going, and Amsoil makes sure it does.

I recently purchased a new Benelli motorcycle. After the 700 mile break in period, I changed the engine oil to Amsoil and decided to start using the upper cylinder lubricant fuel additive. Bike performs well, sounds great and maintains even engine temperatures. I also made a trip to South Dakota and back, adding this to every tankful. Good stuff!

Started using this product more regularly in between cycles of the PI additive. Have definitely noticed better maintained fuel mileage in between oil changes when using this.