Customer Ratings & Reviews

I installed a computer chip to turn off my gas cylinder deactivation system. My gas mileage should have dropped from the high 17s to high 16s. I put amsoil severe oil (80/90) in my rear differential and used PI gas treatment in my fuel. My gas mileage went to low 19s. Did my mileage go up because of the fuel additive or severe oil in my rear differential ?

Absolutely phenomenal engine and gas treatment.

Best fuel additive on the market!

Great product as I use it to keep my GDI gas motor clean of carbon deposits and running smoothly!

Makes vehicles run like they should and the mileage difference is worth it!

Never a hiccup.

This gasoline additive is way better than the other additives I have tried before. My engine is smoother and quieter. Worth the money!!

St. Louis gasoline is 10% ethanol and 195,000 miles with 12 oz Stabilizer every full tank, no oil lost on dipstick, will keep the car running strong with the Dinan stage 1 engine and tranny software. I

I use this in all of my cars at each oil change and at the halfway point to the next oil change. I use this treatment when I work on friends cars and they always say that their car has a lot of pep and thank me for the great job.

No complaints so far, seems to allow my cars to run a bit smoother after using!

Have been using the P.I. Improver since AMSOIL stated making it. Have used other AMSOIL in everything I can get it in since 1983.

PI improver really gave my Audi A4 more pep right off the bat.

Used Lucy’s gas treatments in past but this was noticeably better. Felt like I had more HP

This additive make my car a monster

Seems to work fuel mileage did go up

I have been an Amsoil wholesaler for many years now and hands down this is by far the most superior product you can buy and install in your vehicles. I use all amsoil products and have never had any failures whatsoever !

By far this is the best fuel injector cleaner and fuel system cleaner as well.

I have a high performance engine that is a real gas-aholic. She is a heavy drinker, so any improvement in gas mileage is much appreciated. I've only used it once for the first time and I already have a 3 tenths per gallon increase in gas mileage. That is a 10% increase in gas mileage for my heavy drinker.

This stuff just works. Promises a difference in just one tank and as promised it works- more horse power and smoother running engine

My 2,0 ford runs direct injection, puts the injectors inside the combustion chamber where carbon can be a problem. P.I. performance Improver really keeps injectors, valves, and piston tops clean. Works Great