Customer Ratings & Reviews

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.

trying to do what I can to help keep the carbon buildup to a minimum.

Have used Amsoil PI in past. First time in our new 2022 TRAIL BOSS LTD 2.7T 4 CYLINDER using E15 that is rated 86 octane average. It has 24000 miles on it and the PI is noticeably improving the burn. I am retired tribologist from a major OEM and did chem testing of fuels and lubricants for 45 years. Most additives don't work nor will they mix properly cold and via gravity or splash. Amsoil knocked this chemistry out of the park. Smoother idle, cleaner tail pipe and using crappy high altitude E15 fuels my MPG is up. Will and do use oil analysis from SYNTHETIC ADVANTAGE ISO CERTIFIED OIL ANALYSIS to confirm.

The best gas additive I have ever ordered.

Used to clean my Injectors. Zero issues

Used this in my car to clean system. Very good product.

So far so good very happy

Highly recommended

Excellent product. Highly recommended.