Customer Ratings & Reviews

See the story in the previous product review.

Great product but bottle needs better functioning lid. Very difficult to remove

this stuff seems to make a difference, and its good to have a product you can trust

Great product!!!

The first bottle will make a noted change and one every few months will keep it running at peek. Makes a huge change in small engine, and all types of non road gasoline engines

Always improves my Tundras gas mileage.

As the Title says, this is an Absolute Essential part of any Vehicles standard Maintenance Routine, as Crucial as changing the Engine Oil & Filter but this couldn’t get any easier! This is as simple as it gets when it comes to Routine Maintenance and as easy as pumping gas! Once every 5,000 to 7,500 Miles simply pour a bottle of Performance Improver into a near EMPTY Tank and fill-up good for up to 25 gallons! Amsoil’s Performance Improver does the Tough Job - Cleaning the inside of your Engine and Fuel System, from the Fuel Pump to the Injectors - The Valves to the Piston Head and Combustion Chamber! I highly Recommend this Gas Additive to all my friends, family, and anyone trying to keep their Engine running at it’s BEST, in a “Like-New” Condition, no matter if your Engine is Brand New with only 10,000 Miles OR has worked hard for over 200,000 - Whatever the case - this Additive is a MUST!!

I add one bottle every 4,000 mi to my truck and suv to keep things running smoothly

The PI Performance Improver made my Lexus GS350 and Toyota Camry feel/run smoother. I use a bottle after every oil change. Highly recommended!

I use this before very oil change just to keep things cleaned up in the fuel system...works great would recommend as I would for all there products...you want the best then use the best amsoil...

So I have been cheating and using amsoil 100/1 outboard oil to do the same thing for years. It reduced oil consumption in 2 honda cr-v's and the mileage is up slightly in all our vehicles. Great product

Poured the bottle in and no more hesitation in the throttle. Took the truck through the mountains of West Virginia and Kentucky and it never struggled to maintain speed. So far, I'm a believer!

This is another quality I am is all your product that you should use his part of your maintenance on your vehicle! You will notice a performance increase not only in power but gas mileage is well!

I used this product in a 01 Toyota 4runner limited with 87k miles. I have never used an additive before in this vehicle. After going thru a tank of gas I can happily say that I noticed a big difference in acceleration. I would recommend this product.

Good product this with new oil and filter have got my vehicles running smooth.

Improved gas mileage and performance. Will use regularly from now on.

I've been using this for over a year now. It has improved the way my truck runs and starts. My truck is 21 years old and since using this, it starts right up and has quicker and more crisp throttle response. It brought new life to an older engine. I highly recommend using this product if you have an older engine. I'm positive it would keep a new engine running at peak performance as well.

PI had been a product we’ve been careful to keep on our shelf. We believe it makes a big difference in the performance of our vehicles. We don’t use it on every fill up but usually every 3. May not need it but the engine seems to run smoother with it. Would I recommend this...absolutely.

Effective gasoline additive that smoothed acceleration. Good product.

My wife's tahoe was getting in the hundred thousand mile range..started noticing some power loss...truck is right back to how it used to be