Is this a good fuel for trainers? It is the cheapest I can find online:

15% Nitromethane
20% Lubricating Oils
(1/2 Castor, 1/2 Klotz)

For 2-stroke model engines. A more powerful fuel for those times when you need just a little extra performance. Same terrific idle and throttle response as CHAMPION "10". Smaller engines in the .049-.19 size range will generally start and run better on higher nitro fuels.