earlwb

Many of the RC car specific glow fuels have a lot less oil in them. Sometimes as little as 8% oil in the fuel. So they get the extra power by having more methanol and nitromethane in the fuel as compared to model airplane glow fuel with 16% to 25% oil in it.

I think the RC car fuels evolved like that over time as the RC car people kept wanting more power and speed out of the engines. Plus RC car engines usually have a very short life anyway.

Anyway, it is why I always tell people to not use car fuel in a model airplane engine. When you think about it, a RC car engine doesn't go full throttle for every long, they usually run in the midrange throttle range a lot with short WOT bursts for the straightaway. So the engine tends to load up with extra oil at low throttle settings and blows it all out on the WOT burst, then repeats the cycle around the track. Someone a long time ago figured out how low they could go on the oil content in the fuel and still have the car engine work.

But with a airplane engine, most people tend to fly WOT or full throttle all the time. So then there isn't enough oil in the car fuel to support the engine properly.