Amsoil P.I. Gas Additive (Injector Cleaner)
 

I've used this a few times now. It seems to have helped in fuel injected cars, but not much (if at all) in the carbureted Caprice.

AMSOIL P.i. Performance Improver Gasoline Additive

http://www.amsoil.com/shopres/products/900px/API.jpg

Attempt 1:

1984 Caprice - 305 V8 Engine Carbureted, Roughly 117k Miles:

It doesn't seem as though it worked in this car or if it did, it didn't benefit the fuel economy. I also used 2 bottles. However, if I remember right, I had already steam-cleaned the combustion chambers by pouring a little water down the air intake.

Attempt 2:

1990 Mercury Grand Marquis Wagon - 302 V8 Engine, Fuel Injected, 233k Miles:

I was getting 18-20 and afterwards, got 22 in the same general driving. For taking up just under 1/10th of a gallon, this additive had to have done something good, especially since the fuel filter hadn't been changed when I did this.

Edit: I later learned the filter was rusty on the outside, and it was so dirty inside that the gas that came out was dirty. The additive seems more likely to have helped here.

Attempt 3:

2001 Impala w/3.4 Engine, 40k Miles (roughly remembered: )

This car was initially getting 20 MPG or so while I was putting 1-2 ounces of Renewable Lubricants' Injector Cleaner in with each tank. I then put 9 Oz. of Amsoil P.I. in one time and I'm not sure whether I saw much of a change or not; the car gradually went up to 25 MPG in the same driving conditions. I recently added a full bottle and Father was driving this car on longer trips but only for 90-100 miles these last two tanks; the car has gotten 31 MPG these last two consecutive tanks. It's rated to get 32 HWY but 2/3 of the driving was closer to city driving; 3 miles to and fro work and 4 miles to and fro the grocery store.

EDIT: I think part of why I got astronomically high figures is because it was a short tank, and I think the pump shut off too early. The additive might have helped something, but not that much.

Attempt 4:

2005 Explorer, 4.0 Engine, 153k Miles:

This Explorer was struggling to get 15.8 MPG when I first got it, then when I added the Performance Improver and ran at 70 - 75 MPH on the highway with Overdrive off (to rev the engine harder,) the MPG figure had a noticeable increase afterwards.

I don't think this car had seen injector cleaner before, over 153k miles, so it seemed to get a good cleaning that stayed. I later heard that this additive also puts some lubricity in the fuel, but the cleansing did work well.

Conclusion:

I think the 1990 Mercury and 2005 Explorer benefited the most from the additive. The Carbureted Caprice, hardly at all (if at all; ) and the 2001 Impala? It had low mileage, and while I did think I saw some benefit, it was a short tank that might have been inaccurate.

Has anyone else here used this Amsoil additive? It might require a couple treatments on severely dirty injectors, but I have recently read another post at this forum about injector replacement giving higher MPGs due to finer fuel atomization, so perhaps there's a similar case here?

I tried the Redex version, but didn't notice any difference.

https://images-na.ssl-images-amazon....L._SL1500_.jpg

Techron™ twice a year in our Vibes.

Most of the gas around here, these days, claims to have various additives in it, and honestly these days cars don't seem to suffer from fuel-related issues like they used to. Even the older vehicles (which most are in my fleet), so that discounts it being due to more modern engines. I haven't noticed any appreciable effects of injector cleaners in ages, and I assume this is why.

In USA, "Tier I" fuels must contain an EPA-mandated minimum "cleaning" content; however, MOST major fuel companies (but NOT all) are advertising their respective fuels as having MORE than the minimum.