Customer Ratings & Reviews

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

I use this all thru the year in my colorado and wife's equinox.We actually see an improvement in gas mileage and performance!

Grateful lubricating all your engine parts and fuel line and stuff like that

This product is really great at cleaning out my fuel system. IT improves performance and mileage better than any other product I have used.

I have been purchasing the Performance Improver Gasoline Additive and Upper Cylinder Lubricant Additive since last year. The ordering process is simple, shipping is rather fast and most importantly the products work. I have noticed improved fuel mileage and a smooth running engine. Amsoil offers many other quality products as well. I do not have any other needs at this time because of warranty service provided on my car.

I use Amsoil oil in everything i own i used this additive in my 99 ram with the 5.9 gas engine and it did seam to improve the engines mileage