Customer Ratings & Reviews

Helps with upper cylinder cleaning and fuel efficiency. Not sure exactly what the average mileage is raised but near 1 to 2 miles per gallon.

Excellent product that does exactly what it promises. Same road trip, started at 20.5 mpg over 100 miles. Added Performance Improver at next fill up in my 165k mile 2014 GMC Sierra with the 5.3L L83. Increased fuel economy and throttle response over the second half of the trip. Got 22.1 mpg. This improved fuel economy has persisted. I have filled up 5 times since then and the improved fuel economy is noticeable. I highly recommend this product.

I use the gas additive once a month and my engines runs clean and smooth!

It worked as advertised just like every other product I have used from AMSOIL.

I had been experiencing a rough idle and acceleration with my 2016 VW with a V6 engine. I previously tried several other products to correct this. None worked. Using one bottle improved the issue and a second bottle eliminated it entirely I now use one bottle every few months as a prevention

Made my car run great again.

I’ve been using P.i. additive for a few years and feel it works well

Install this in both my vehicles every 5k oil change, keeps fuel system especially injectors operating properly.

So my older tahoe will ping slightly if I use regular gas.. ran a bottle of this thru her and ping is no longer present with regular gas

put Amsoil in my snowmobile after sitting all summer, perked that 4 stoke into a smooth running machine..

We only use Circle K non-ethanol gas now. This helps keep the fuel injection systems clean on our collection of 1990 to 2016 vehicles.

Excellent stuff I noticed my vehicles running a lot better

I didn't notice any difference. The car had no performance problems beforehand.

Comparing this to gumout product. This seems to perform better and get better results. I would highly recommend people to give it a try.

I use this regularly in all our vehicles. Keeps them running like new and with high quality gasoline can give you better fuel economy.

The P.I. Is a noticeable difference in improving the performance of my Ford 4.6L V8 SportTrac AWD.

Amsoils P.I. gas additive really does work, the extra power it adds is actually noticable!

Great product. I have been using it for years!

This is the best on the market.

Awesome product used in my truck and could tell a difference