Someone suggested that I add 4%toluene to gas ratio to help prevent pinging. Is this the correct percentage. So what it comes out to is for 6.5gals of gas add 1qrt of toluene. Is this the same startex toluene that you get at a paint store? So what does it basically up the octane level? I always use 93, I just thought I try this till I get new plugs. Has anyone ever used aviation gas instead of race gas? The only difference I think is that aviation fuel is leaded and race gas is not. Do you think it will hurt. BTW I have no cat.