If ya want to up your octane rating Tollulene will do that, + there are several octane boost products available off the shelf but they R not cheap.
Although a 20 lit drum of tollulene won't be cheap either but certainly cheaper than the smaller ready to go product likely the same stuff anyway, Of course read the instructions and know what your doing before using it or you may/probably will destroy the engine.
If money is of little importance unleaded avgas will make your beast run very well, having not bought any for a while I can't say what it's worth now days but it's available (after signing a waver for it's non airplane use) available in both the same and several higher octane (RON #) ratings than premium unleaded which is about 92-95 RON and as it's made so your plane won't fall from the sky it's a lot cleaner than the crap you get out of any servo tank.
For the lazy classic BP 100 or the good old Shell 115 MB will run fine in any stock car / bike with no jet changes whatsoever, BTW the 115 is not methanol (not even close), its RON # is over 160, purple in colour and burns similar to metho, same gear the CART open wheeler guys use.
I used methanol in my racing bikes (now illegal) but it would make any 6 run like a V8, easy, the injected engine would be a nightmare to run methanol, so be prepared for many long nights with changing all the fuel system, high flow injectors, bigger pump, yada yada, get it wrong and you WILL burn the valves / pistons away like they were made of plastic, (not for the beginner) and it DON'T mix with petrol, so don't try! the basics of my personal race days was to simply double all jet sizes and it would probably start, the long tuning road started from there, BTW they were all race only engines that had to last the afternoon only, sometimes less LOL.
A novel liquid and great stuff for instant huge HP gain, with the carby inches from a very hot enging there will be ice on the outside of the carby bore where the liquid fuel is vaporised into the a/f mix it is very cold, roughly where just after the carby butterfly, burning Shell R-40 vegie oil and methanol ya didn't need cocaine, addrenalin from the HP was damm good stuff.
