To be honest. About any fuel will suffice. as long as its got plently of lubrication. I use wildcat 15-20% and it works just fine. Try ordering from Morris Hobbies, they ship by the gallon instead of by the case. and have good service. The only time I've had to be choosy with fuel, was with my monster trucks. Airplanes and heli's have plenty of air moving freely over the engine's head to keep it running cool, whereas a truck has an enclosed engine. If you've ever flown a plane with a tight fitting cowl, you know what I'm gettin at. Just my 2 cents! take care