Customer Ratings & Reviews

This top cylinder oil will minimize wear in the upper half of the cylinder, lubricate the injector needle and eliminate corrosion in the fuel tank, all without harming the motor oil.

Bought the lubricant (and engine flush) specifically for a Toyota with the oil-burner engine (due to a factory defect that Toyota won't hone up to fixing). Love the SUV and mine isn't burning oil yet, so I'm counting on Amsoil to keep the engine clean and lubricated to prevent the problem from ever occurring.

Had car at dealer for injection service and didn't notice this big of improvement. I won't be using at every fill up but once every few months for sure!

Ran in tank of gas after the fuel system cleaner. Noticeable improvement in the smoothness of acceleration, remedied some slight lagging. Will use regularly from now on.

Boosts fuel milage and it actually helped my fuel pump. My fuel pump developed a noticeable "whine", which they pretty much all do. But mine was louder than normal. Since I started using this product, the louder whine went away. The pump sounds like it did when it was newer. It eliminated that loud whine. Awesome product!

Used this at every fill-up when I had my 2014 silverado 5.3L L83 before I got a diesel silverado (3.0L Duramax LM2). I have used this at every fill-up for my wife's Durango too. Again, quality products. Never had any concern or issues with Amsoil products across the board.

This and my decision to switch to Amsoil 5W30 in my 1999 Chevy/5.7L made my engine as quiet as can be. Highly recommended!!

This seems better than other brand. My average mpg was 23.3. it's now 23.6. mpg. To early to tell. But it's never been up to 23.6 mpg

I usually use Performance Improver at every oil change then use upper cylinder lubricant at every fill up thereafter. Bottom line engine runs great and smooth and mpg are better.

Not only does this product Lubricant you upper cylinders, it also increases fuel mileage! My mileage in my 2018 RAM 1500 w/5.7 jumped an average of .5-.8 mpg when using this product! And if it lubricants well enough to increase mileage think about the added longevity it’s adding to you engine as well! Great job Amsoil!

I use every 5,000 miles. Helps keep my old car run like new.