Customer Ratings & Reviews

I have been using this product for years. I actually checked before and after using with a bore camera and there was a significant difference with carbon buildup. Combustion chamber Is a lot cleaner after using P.I

I really can't tell yet if it improve the gas mileage or performance yet because I have not driven for yet, but if it is the same stuff I us in 2010 then it will be great.

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

Absolutely the best complete fuel system cleaner money can buy. Throttle response, engine performance and measurable computer analytics will substantiate the the results one bottle will produce.

I like my vehicles to be in best performance. I use Performance every 5000 miles when I change oil. Runs great !!

It's always good to keep your engine at it's best performance. I believe this product does just that!

Engine runs smoother with better performance/mileage.

Phenomenal product compared to others. Saves you money when it comes to gas mileage . Tested 3 bottles with 3 full refills on my v8 truck and felt reduction on my refill on the 4th time since I still have half of the tank left . Will definety buy some more to save on gas refills and adding more power to your engine...

I use this at every oil change. Can tell after it has ran awhile in the Engine. Smother and better acceleration.

A+awesome

I use AMSOIL PI gas treatment in all my vehicles. I noticed my fuel economy go up during my longer trips. The greatest benefit for me is when I use it in my carbureted Big Dog Choppers. They had started to get gummed up and sluggish but after I added just a little PI gas treat they started running noticeably better.

noticed a substantial improvment the first time I used it.

This is the only additive that improves the way my cars run. My Ford Edge has direct injection and P.I. is very noticeable. The 2007 Volvo also responds quickly. Thanks for another great product

Always good products and service from my friend Rich Day!!

This stuff works! Empty into a near empty gas tank, then fill up. It will give you noticeable increases in power by cleaning out the deposits in your intake. I use it every 3000 miles. My Audi TTS just simply runs better now since using this product. Couldn't be happier!

I had tried many different brands of fuel system cleaners, and none ever had particularly good results. For a while, Chevron Techtron was about the best that one could buy, until the advent of AMSOIL P.I. Performance Improver. The AMSOIL version was the very first in giving a noticeable improvement at once. "At once" like when leaving the gas pump. I've been buying AMSOIL P.I. Performance Improver for years now. And whenever I buy a used car, the first thing I do is add two bottles of AMSOIL P.I. Performance Improver and fill it up with Shell V-Power gasoline. That's a truly great combination to clean out a neglected fuel system. I also use it every couple of thousand miles in my cars for maintenance. I buy it by the case and keep it on hand for my use and if someone else runs into a fuel issue. The only thing that I don't like about it has been the change to the red bottle. YUK! I liked the former bottle much-much better, both in appearance and in being able to see the actual product through the clear bottle.

Gained mpg after one use.

Been using this for several years. My Ram loves it!

can tell a difference after using P i Performance Improver Gas Additive I will be using it again

I hooked up scan tool and STFT and LTFT was 12.8% and 6.9%. (short term fuel trim and long term fuel trim) After using this 0% that's a perfect stoichiometric ratio. For just riding in town. I would suggest if you cannot drive 30 min on highway to put vehicle in sport mode a couple of uses. Great product