Boosting your pump gas Octane rating - 

I buy toluene in 55 gallon drums from a local chemical supply outlet, but
most people will not do this.  One of the major components in regular
pump gas is toluene and is often used (for many years) to boost octane.
Some people mix it as follows:

1/2 gal toluene
two oz. dextron II ATF
six oz "motorhoney/powerpunch"
1/2 gal Coleman stove/lamp fuel
quart of delstar enamel reducer or equivalent
mix well, add to five gal can and top off with premium unleaded
use as an additive 1-5 ratio

Basically I use Toluene, ATF, and diesel mixture to raise the octane
from 92 to about 93-94.  I don't know if many people would want to
go to this trouble unless it benefits them as much as it does me!
My Audi V8 Quattro has a sophisticated anti-knock computer program
that detunes (retards) the engine if it detects detonation.  However,
with the 94 octane, I get the full 250 HP design of the engine and it
goes like a bat outta hell!  
Richard Moore (richardmor@aol.com) May 2002

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and another

How to make your own octane booster (this is the basic formula of one 
of the popular octane booster products). To make eight 16 ounce 
bottles (128 oz = 1 gal): 
100 oz of toulene for octane boost
25 oz of mineral spirits (cleaning agent)
3 oz of transmission fluid (lubricating agent)