Great product value.

Use it in my tuned 2018 540i 450+HP 500+ tq. I run higher octane fuel 90% of the time, or an ethanol blend so every couple of tanks I run normal 93 octane and a bottle of this and the P.I. Keeps things running smoothly and clean. I use all Amsoil fluid in all my vehicles (engine oil, transmission fluid, diff fluid) and have never had issues or experienced any abnormal wear.

Some noticeable difference in the engine performance after adding the Upper Cylinder Lubricant.

Helped improve the running on a used 2007 Honda Accord.

Have been experimenting with upper cylinder lubricants since last year. In a 2018 Duratec engine, it appears to boost mileage about 3/10ths of a mile per gallon. Added on top of Amsoil's own research showing reduced wear at the valves, this makes it great choice for engine durability. I add at a rate formulated per gallons of gas needed for refill. This makes it more economical to use by adding the remainder to the next refill (properly measured). The bottle neck does catch on this Ford's capless gasket, so I still need to use the car's provided funnel to add to the tank.

I noticed a slight ticking in my valves on my 2013 F150. After adding this to a tank, the ticking went away.

This product is exceptional! It really does what the say it does. I love these products from Amsoil!

I’ve used others! But with this product, I can actually feel a difference!

I had a lifter or two ticking in my high mileage 4.2 l engine in my F150 pickup. After one bottle no more ticking.

My cars start faster and get better fuel mileage

Helps a lot with the mileage And the performance

Use it every couple of tanks of fuel

I have been around Amsoil products most of my life. They are number 1 in lubrication as far as I am concerned...

Engine is running better. Will try any of Amsoil’s products I can.

I’ve been using it weekly in my car over the last 2 years.

I use this product every fill-up of gas because I notice a better idle and better MPG.

I put a bottle in every tank full of gas because it adds about .3-.6 MPG in my 2018 5.7 RAM. To me if it's adding lubricity enough to add MPG's it should add extended life to the engine as well!

Great product but bottle needs better functioning lid.

Great product. Use it every fill up. Cheaper than store bought products. Only issue is the opening of the seal. Sometimes the tab pulls off and you have to use a finger to break the seal. Seal needs to be made like performance improver so the solvent doesn’t get on your hands. Great product other than that.

I use this on long bike trips when the temps are high to help keep the top end of the engine lubricated. I add 1.5oz to a tank of gas (5 gal) maybe every 2 or 3 tanks. About 1 bottle every 8 to 10 tanks of gas.