"Airplane" fuel is just regular glow fuel. R/C car operators make a distinction because "Car" fuel has lower oil. "Airplane" fuel usually has 18% oil or so. "4-stroke" fuel has 16% oil or so. The only difference between the different fuels is oil content, but the ingredients are all the same...oil, methanol, nitromethane. The oil can be castor oil or a synthetic lubricant that works in model engines...there are different ones. In North America, Klotz synthetic oil is usually the one, and it's also mixed with castor oil....depending upon the blend being made.

"R/C car" fuel was developed by racers because it clears-out very well when throttle is applied. Car racers are on and off the throttle a lot and quickly. Airplane fliers are slower and smoother on the throttle. With a car, any hesitation when the throttle is changed can cost a race. Lower-oil fuels will clear very quickly and give faster throttle response. The low-oil fuel will provide lubrication as long as everything is ideal, however, get the slightest bit of dirt in the engine, a bit of air in the lines, some vibration-induced fuel foaming, and your mixture goes lean quite quickly. If you're a dedicated racer, though, an engine rebuild per racing weekend isn't out of the question. If you're a backyard "basher", then you want engine life over maximum performance.