Customer Ratings & Reviews

I have been using this is my 1/2 ton farm truck and wife's 16 Tahoe. It really cleans and have noticed it neutralizing the fuel. My fuel trims and changed and a big notice in my alcohol content is way better. I have also noticed we do not have to complete intake cleanings near as often. Helping with carbon build up. We have noticed a slightly better fuel milage. This has slowed the demand for "fuel tank evap as well". Again, THANK YOU AMSOIL.

Love all the Amsoil products

I've used PI for almost a decade now and as far as I'm concerned, its one of the best products AMSOIL makes. While I use it with my cars - and if you start using it early in a car's life, it's going to help keep it from having fuel injector problems - I also use it with small engines. I have a 30AMP generator that wouldn't start at all. I had used fuel with ethanol in it before I became aware that could cause issues. After multiple attempts to start the thing, including using Power Foam in the carburetor, no dice. I figured I'd have to take it to a shop for repairs, but I decided to put in PI with some ethanol free gas and amazingly, that generator cranked up. Shut it off and started it again the next day, no problems starting. Put a half bottle of PI in there with non-ethanol gas and it ran until it was out of fuel. That was 7 years ago, and that generator hasn't given me an ounce of problems starting/running since, including during the Texas deep freeze of 2021 when we lost power for 3 days in sub-20 degree weather. It ran for ~ 55 hours pretty much nonstop. Not going to say PI is magic or a cure for bad maintenance/operation but it worked for me.

Great product running it in all of my vehicles. Noticed a big difference in the performance of my vehicles. Used to use a different product, now I'm team Amsoil for sure.

I can see a difference after using

I’ve been using Performance Improver for years, currently my 22’ Toyota & 2013 Honda. Improves gas mileage & gives you an engine boost.

I have using it for a while , it does the job

Definitely a notable difference in my 2016 F350 6.2L Flex Fuel. Affordable, quality product that works!

Fuel Mileage increase is noticeable. Lasts a few tanks after.

I always use this on my last empty tank 20 gal fill-up before changing my 2013 Silverado 6.0 gasser's oil. I also use it along with the Upper Cylinder Lubricant too at the same time with good results. I definitely notice my truck running smoother for a pretty good long while afterwards. Give it a shot!

As the product cleans during the tank of gas usage, gradual improvement in performance is noted and definitely is noticeable after running the entire tank of additive containing fuel through. I haven't calculated the actual mpg increase, but it has definitely helped.

Great value for a product that works as advertised.

Car runs 100% better starts instantly in cold weather improved mileage

I couldn't believe how quickly I noticed a difference in performance in less than 100 miles smoother,stronger on a 160k plus Corolla

The AMSOIL Performance Improver Gasoline Additive has improved my gas mileage and keeps the engine running smooth. I use that in between using the Upper Engine Lubricant. I would recommend these products for any vehicle.

Bought a 12 pack, started adding 1 every fill up, checked mileage before and after, maybe 1/2 mile per gallon better. For the cost per bottle, doesn’t justify 1/2 mile per gallon. Sorry….

Dose a great job for cleaning out an engine that has carbon build up problems. Helps with fuel economy a lot also.

Put this in my 2016 Honda Pilot Touring and it seemed to make my Pilot run smoother. It could be a Plasibo effect but I never got the same feeling when using another brand Seafoam.

Use all your products for my car

Use 1 bottle in all our 5 vehicles 2 times a year and have noticed slightly better mileage and drivability. Great product at a very reasonable price.