Not how the directions say but I usually put a few oz in with each fill as a maintenance dose. I usually buy nonalcohol top tier gas which means it has a good amount of cleaners added at the blender. I drive my daily drivers over 300,O00 miles and so far no O2 or fuel injection problems. Fuel pumps usually last about 200,000. I drive my dailies over 300,000. Also have '54 inline 6 with 6V points ignition. Plugs stay clean for 10,000 miles which is my replacement interval.
Bottom Line
Yes, I would recommend this to a friend.
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4 star rating
By 
Anonymous, 
a 
Verified Buyer 
on 
October 30, 2020
I use this product in my truck to keep the fuel system clean works great,,, as all amsoil products do,,, would recommend... 👍
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
By 
Anonymous, 
a 
Verified Buyer 
on 
October 23, 2020
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
Works? Confirmed Better Than Any Other Product I've Used!
By 
Amsoil PI Performance Improver, 
a 
Verified Buyer 
from 
Virginia  
on 
October 19, 2020
I can confirm that this product works "as advised" on five different vehicles in my driveway. A 2013 Charger R/T, 2015 Charger R/T, 2004 Jeep Grand Cherokee Limited 4.7, 2008 Ram 1500 5.7, 2011 Infiniti M37x. Better MPG (noticeably better), better throttle response, faster, easier starting, smoother idle, quicker, more effortless acceleration and all around stronger running engine in ALL 5 vehicles with just 1 bottle/treatment.
I've been using NOTHING but Amsoil in all of my vehicles for over 15 years and I've never had any problems or complaints, just positive feedback to pass along. I'll never change to anything else!
Have used this for years on multiple cars. After running it through one tankful of gas in our current Subaru I can feel an immediate difference in engine smoothness, throttle response and acceleration.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
PI Performance Improver
By 
Charlie, 
a 
Verified Buyer 
from 
El Paso, TX 
on 
October 19, 2020
I started using PI several years ago. I had a vehicle with a rough idle, and suspected a dirty injector. After the first use of PI the engine smoothed out. Ever since I had added PI to every fill up just to keep the injectors clean. With the gasolines of today I figure this is a good way to keep the engine running smooth day after day.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
By 
Anonymous, 
a 
Verified Buyer 
on 
October 18, 2020
Bottom Line
Yes, I would recommend this to a friend.
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2 star rating
Not impressed
By 
Vette guy, 
a 
Verified Buyer 
from 
NV 
on 
October 18, 2020
Not impressed, shipping was also charged even though i entered the discount code. I suggest you buy gasoline additives elsewhere.
Bottom Line
No, I would not recommend this to a friend.
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5 star rating
Amsoil delivers!
By 
GT75, 
a 
Verified Buyer 
from 
Orange County, CA 
on 
October 17, 2020
Using the PI Performance improver in my car for over a year. This product has increased performance and given me a smooth ride. Definitely recommend PI Performance Improver.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
P1
By 
Roll Tide, 
a 
Verified Buyer 
from 
Al 
on 
October 17, 2020
Excellent product and keeps your car/truck engine with a clean fuel system. Use as directed for optimal results.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
By 
Anonymous, 
a 
Verified Buyer 
on 
October 16, 2020
Have not noticed any real difference in the mileage factor increase or otherwise when using the PI Performance. I do still purchase to help keep the system clean and at peak performance. My Ridgeline has 140,000 miles and not been tuned up yet for it's first time, because there is no build up on the plugs and she still runs like she always has and the engine is clean due the PI Performance and the Signature Series Synthetic Amsoil used. I would recommend it's use increased mileage or not just as a preventive measure to keep the system clean.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
By 
Anonymous, 
a 
Verified Buyer 
on 
October 16, 2020
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