This is from RB Racing site big Bonneville motorcycle guys

When Honda was spending 500 millions dollars a year on their V6 Formula 1 Turbo motors they ran a mixture containing 84% Toluene (114 Octane). It has excellent anti-detonation properties and increases your octane rating. If you are running 92 octane pump gasoline and you add this stuff, your octane rating will be changed by the formula:

[(Quarts Gas x 92) + (Quarts Toluene x 114)] / (Quarts Gasoline + Quarts Toluene).

For example, if you add one quart Toluene to four gallons of gasoline, your Octane will increase one point from 92 to 93. Add two quarts to four gallons and you get an Octane rating of 100. For you high boost junkies this is something to ponder. You can buy the product in hardware stores. Xylene has a higher flashpoint (less volatile) and has and octane rating of 117.