Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Gil, I know you have mentioned at least a few different "formulas" for running these little H&M engines. Just wondering if you have settled on any one as being "best" for overall performance and operational qualities?

I've been using white gas (Coleman fuel) mixed about 25 to 1 with Marvel Mystery oil, based on an earlier suggestion of yours (I think???), but also managed to score some 100 octane aviation gas (also at your suggestion I think???) which I have run at about the same mix ratio and found both to be adequate, though I must admit to being a bit worried concerning the lead content in the avgas.