Most of the people that i know, including myself and my brother is run Xylene (Xyleno) paint thinner which has an octane rating of 117 , according to the alyeska fuel plant you can mix up to 45% Xylene with regular unleaded, i usually run a 12:1 ratio. Toulene works the same, except the octane rating is 114, so you will see less gain as far as knock resistance. in order to add lubrication however you should add MMO or i cup of synthetic ATF per 12 gallons so the harshness of the chemical doesnt damage seals or fuel system components.