Customer Ratings & Reviews

Use this in all my cars at fill to keep injectors cleaner and run smoother. I also like the lubrication benefit for the upper cylinders.

I notice an increase in milage in my 2021 4cyl Silverado of 2mpg

Have not been able to detect any improvement. Possibly changes are so minimal that it is hard to notice a change. I am not saying that the product is defective but might need some test equipment to pick up a low-lying improvement.

Purchased this for my wife and daughters cars both noticed an improvement right away in both smoothness of the engine and a mpg.

Excellent product made to clean & lubricate your fuel system..

Driving a 19 year old car and with gas prices as they are, you need to get as much mileage you can out of a gallon of gas, car runs better, more engine power too.

This upper cylinder lubricant keeps our 2021 Lexus NX300 running smooth as silk we use every other tank full it fights the moisture in todays gasoline and keeps injectors clean plus it helps keep the cylinders clean along with using Amsoil 0w20 XL motor oil I’m a big fan of Amsoil I won’t use anything else u might pay just a little bit more, but a little more now is better than a rebuilt or new engine later folks do your homework check out Amsoil u will be glad u did

I used it pulling a heavy trailer. Went out empty, came back loaded and used a bottle for return trip. Truck just seemed to do a little nicer. Got back and averaged almost same mpg as empty. Really like it.

I have been using this for years in all my vehicles. I trust Amsoil to supply me with the best products to protect my vehicles. I have never had an issue with any part of my vehicles that are Amsoil protected.

Excellent product with results!

Great products, Fast shipping, Great savings with club ...

Threw this in and and changed to AMSOIL full synthetic 5w30 and my 350 purrs like a kitten. Thanks, highly recommended!!!

I plan to keep my vehicles running top condition and with upper cylinder lube I trust that.

Engines need to be lubed and this product seems to be the ticket for that added help.

Both my vehicles are fairly new but I use Amsoil upper cylinder lubricant regularly and both engines seem quieter than when I first purchased the vehicles. Very impressed.

I add UCL to every fillup and notice my car runs better in terms of smoother acceleration, even though I use high-quality gasoline (Costco, Shell, Mobil or Chevron only). If they don't increase the price I'll continue to add one with every fill-up.

Really depend on this as I do a lot of towing.

Put this in my mower and generator. Both run a lot smoother

The stuff works great, car still runs like new with over 200k miles. Little disappointed that I spent over$100 on my last order and did not receive the shop towels

Overall product quality is a 5 stars, Amsoil requiring you buying a bunch of bottles is 2 stars at best and I rate this overall 3 This product evened out my idle and my engine is running much smoother on a 2007 Scion tC, I also put it in a 2019 Buick Encore which seems to have had an immediate effect of better gas mileage. The problem with this product is you have to use it consistently (emphasis here), which requires you to buy a bunch of these bottles, I think Amsoil should sell it as a large bottle so you can divvy up your own from a measuring cup or dispenser, that would save on the plastic and hopefully bring down the price. Sell it in quarts or higher quantities and provide in the instructions the recommended administered quantity for the treatment of gas. I really like this product so far but cant justify buying 100's of small bottles, when they could just put it in a larger jug, as this is the only product I can find that I trust... I will be stuck paying for it begrudgingly.