Customer Ratings & Reviews

I use the P.I. every 5k miles in all of my vehicles to keep the fuel system working at peak performance. I know I get the results having pulled the fuel rail off my truck at 162k miles. All the fuel injectors were completely free of any carbon buildup and working like factory new!

The AMSOIL P.I. fuel additive works well, it quiets the engine, better performance, and makes the engine run smoother.

This stuff is great!! Where I live currently, the gas is junk but after one use of this product my truck runs better and is getting better gas mileage. I put it in my wife’s truck as well and literally after one use it has improved fuel mileage and it runs better. Will definitely be purchasing again. Looking forward to becoming a dealer and representing AMSOIL the proud way.

Trusted brand works great

I wish I'd known about this sooner! I only put about 75 miles a week on my car, stop and go to work and back. Bought my car used so I assume it already had some carbon buildup. Noticed quite a difference the first day! Will definitely use this once a year to keep it clean and responsive.

Best injector maintenance cleaner and combustion chamber cleaner on the market.

I’ve used this fuel system cleaner before going on a long vacation drive and I noticed that my car and truck ran better after using it

I use this every 4/5 tank of gas. Not only does it clean the injectors, It make the TT ecoboost 3.5 run amazing!

Smoothed out idle and rough starts

Excellent fuel system product that actually does what it's supposed to do. I personally use a bottle at every oil change.,keeps the injectors spraying instead of squirting.

Had a check engine light on my truck said it was O2 sensor. Had it replaced still came on. Put this in and check engine light has been off ever since

Always does the job! Thanks

I've driven 150,000 km using only this product every year after winter to clean and maintain my injectors. My engine still sounds like it did the day I bought it from the dealership. It works wonderfully.

Good to use when doing a oil change to help the intake clean

Use it every thing I take a long trip

I purchased three products from AMSOIL, The Upper Cylinder Lubricant Corrosion Inhibitor, The DOMINATOR® Octane Boost, and The P.i.® Performance Improver Gasoline Additive I added all three to a full tank but, prior to doing this, I had filled the tank with Top Tier Fuel for this test Shortly after I took a ride, at first, I noticed nothing, but the very next day I put twenty miles on her, and that is when I noticed she ran quieter, and that the pick-up was back I highly recommend this product for older vehicles, and I want you to know, that these products are not a gimmick Check it out for yourself

I added this to my 2021 Camaro and so far it's doing a good job. I will need to update later if it helps with the gas mileage at all.

I had a check engine light for anti-knock sensor on my 2005 1500hd sliverado. I’m thinking I had a dirty fuel injectors and this product cleaned them. Thank you.

Been using the products for years! Would highly recommend any of the products!

I have a 2011 6.2 raptor. My mileage has been between 10.5-11.5 on average. Really depends if I’m doing 63-65 or 70+ MPH. Now I will say that I haven’t used a few additive in my truck in a while. It was time to get some more oil so I decided to get some PI to go along with it. Not even within that day, after putting the additive in my fuel, I considerably noticed better throttle response. On top of that I also was doing the math and my mileage went up to 13.1 miles per gallon on average. I am completely blown away especially right now with gas being over $4 a gallon.