Customer Ratings & Reviews

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

As the title states and works as it should. I use it with the upper cylinder lube and have better throttle response and a little better gas mileage improvement.

Great addictive. Keeps injectors functioning well

Super augment la performance qui est quand même remarquable

Works great and increases mileage

This is a great product. I drive some really old cars, including my lovely 1988 Cadillac Sedan de Ville, and you can just imagine what kind of crud has been building up in those fuel tanks. P.I. helps get rid of the stuff as well as clean out the fuel injectors so that you will get good ignition. You only need to use P.I. every four thousand miles or so, although I recommend that you start out with a more frequent interval. As the price of gasoline has increased drastically, the expense of Amsoil's fuel additives has become less and less of an issue. These additives are well worth it.

I use this at every oil change.

Been using P.I. in my vehicles for a while, and I love that the new bottle is designed to fit in the cap-less fuel fillers on newer vehicles without having to find the funnel they include for emergency fuel-ups. Way ahead of the competition, and a great product inside to boot!

Noticeable gains when using this product, especially off the line.

I have found that using PI makes my engine run really smooth. When idling at a stop light, I can’t even feel the engine running in the steering wheel.

Using it for while now. Been noticing more miles on MPG. Say give/take 20%. That gives me extra day to three on same amount of gas with the a performance Improver!

Never an issue with over 15 years I love this stuf

Started using P.I. Additive about two years ago because where I live in Missouri we use 10% enthanol in our gas and now because of the fuel prices last year it is now up to 15% so I like to make sure my cars fuel systems are treated every 6K mile. I just treated my 2014 F150 that is flex fuel capable and have notice my fuel mileage has picked up 1-2 MPG since the last treatment. I trust Amsoil products and am now using them exclusively in all my autos.

I only use the best for my Civic Type R and Amsoil is the best! Fast shipping great prices 10/10 I recommend them to everyone!

I have used P. I. for many years. I even give a bottle to friends, ever now and then.. We all love it...

In my past 5 family vehicles in Upstate New York, this additive has helped them start esp in very cold snowy winters, while correcting some of the damage caused by Ethanol-Added gasoline. This is the only gasoline additive I use.