Customer Ratings & Reviews

I use this a couple of times a year in all my vehicles to clean my engine. I usually add it before a long trip on the road to get a good cleaning. It's hard to say but it seems to keep my engine running good.

I started using PI when I bought my 2001 GMC that has an 8.1l engine. I does help to improve the gas mileage on my truck. The 8.1 was not built for mileage but for towing. PI does improve the gas mileage. I highly recomend this product.

As with all AMSOIL treatments, this one is no different - it's a must-have for any gas automobile. I use one bottle in my Grand Marquis every 3-4000 miles and my mpg's stay between 19-20 in town (which is 2-3 mpg above the EPA's average estimate for the little 4.6L). 28-30mpg on the highway at 70mph. YEAH. Of course, every fluid in my car is AMSOIL, from differential to engine oil to coolant. I run Sig series 5W-20 with an EA011 filter every 10,000 and I use a WIX 46814 air filter (nothing special in terms of air flow). I also have a coolant filter with the Donaldson P554685 filter running AMSOIL HD coolant. With all of the positives of my AMSOIL-fan-boy tendencies, it really is the best stuff on the market for keeping your engine in tip-top shape. But buyer beware, if you're going to use any fuel treatment from AMSOIL (including the diesel treatments, which I use on my 6.0 - which also runs like a top), have a Swiss Army knife to help you open the lid. The child safety mechanism doesn't work and it's impossible to open the lids without either cutting the lid off or using a pair of channel locks to vise it off. And of course, there is a foil tab underneath the lid that is also very hit-and-miss. I've found that out of a case of 12 (of any fuel treatment), at least 3 of the safety tabs under the lid are defective. They either leak in the box (wasting the precious fuel treatment) or are impossible to remove without a tool (which is counter to the pull-tab design).

Great fuel additive if you are looking to keep your motor clean and running at its peak. This is the fuel additive you need.

Amsoil does it again with a great product and ease of use

This stuff is great! I used to use Marvel's in my oil and in every tank of gas, but my Suburban was starting to slow itself down, the knock sensors were crying all day... I switched to Amsoil and things are looking up! I use Signature series oil and add this PI every 4th tank; no more knock. Very pleased!

I never really believed the effects of these gasoline additives, but this one produced results. My truck doesn’t have that thick white exhaust smoke any more and starts way better than it did before two applications of the performance improver. You do need multiple applications to see any improvement, but my truck only took two.

I use this occasionally just because. I don’t think it does anything for Milage and Not sure about Cleaning anything since I don’t get an INCH MORE per mile or gallon of Fuel ⛽️. And I don’t tear down my Engine to look at valves and Injectors and I don’t own a Bore Scope! It’s too expensive if ya ask me but I switch back n forth between StarTron and this Stuff. Star Tron is $32 per QUART (32OZ) And Treats 1200 Gallons of Fuel! Yes, thats 1200 GALLONS (1200).... a much better deal and probably every bit as good. Even still not an inch a Gallon per mile!!! Nothing!!! Is it worth it??? I suppose it’s piece if mind and Nothing more???

Feel smooth accelerating will buy it again

My 2008 toyota tacoma would sometimes hesitate when accelerating. Not anymore with just one use!

When we add this about every 3rd tank my wife notices the fuel increase and power

EXCELLENT CLEANER

Excellent product! I can tell an instant difference in throttle response. I personally do not see an improvement in MPG, however my friends do. Driving a 2500 with oversize tires I’ve pretty much given up on improved fuel economy.

Never really notice an increase in mileage but it does help if get bad gas and with emissions. Get this for every 4000 miles

This product does EXACTLY what's printed on the label! I gained at least 60 more miles to a tank of fuel and the engine is more efficient and responsive. Great product! Awesome job Amsoil!