A 4:1 mixutre is 20% right (4 parts gas to 1 part toluene)
I read that its safe up to 30% but i wanna be extra safe

4:1 would be a 20% solution. Another question: can toluene be mixed with 89 octane that'* already 10% Ethanol? Here in Iowa I the Ethanol blend is always available (I don't know about other states), so will toluene affect the already-blended gas in an adverse way?

Not worth mixing with anything but premium.
Depending on how much and where you get it expect $8 to $15 per gallon.
I just put it directly in the tank then fill up. As mentioned above do not get it on the paint.
It should work with any gas you can get at the pump. Ethanol, methanol, MBTE should be fine.

don't get it on the paint???? :?

how do we do that? it seems like every time i pump gas i get a drip here or there . . .

what is the secret?

Be very careful. Wait a few seconds after your are done pumping. and shake the nozzel in the filler neck before you remove it. I dont think that i have ever gotten gas on my car....

but isn't it considered playing if you shake it more than twice

yes but my car likes it

I use a 5 gallon plastic gas container to mix it.
You only want to run with 1/4 tank or less at the track.
1 gallon of Toluene to 2 gallons of 94 octane with give you about 104 octane.
Cost is about $15. Cdn a gallon (not cheap where I live) from most hardware stores that sell paint thinners. The downside is the toxic emmissions that are given off when you burn it.
Perrrrrrfect for running that smaller pulley at the track with no KR.
Very noticeable performance gain.
I use it with my Firebird carburated car too with no problems.