Customer Ratings & Reviews

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

You can notice the inprovement

Never noticed 1 iota of difference in the running of our Colorado.

This product it totally outstanding.

Great product , I use it in both of my Infinity’s & my Harley Davidson motorcycle ! Makes a big difference in Performance ! Buy it

Improved throttle response and M.P.G.

I have been using AMS oil for years, it's the best. I started using in my Race Car first then in my truck and my whole family is using it now in there cars, I also like the articles in the booklet very informative Thank you guys