There was a thread like this a while back and he mentioned a specific brand. The mfg of the fuel very specifically said NOT to use their car fuel in planes for reasons I do not recall. May I suggest you look up the mfg on the web and do a little research and maybe even email them for their thoughts on this subject. And of course there will be others commenting here soon I am sure.

Not trying to chase you off either but you could also try the RCU fuel forum at:
http://www.rcuniverse.com/forum/forumid_161/tt.htm
I am sure they will have some ideas there also. Moderators may close one of your threads for double-posting is all. [] Worth a try though.