Basically, Nitro carries oxygen with it into the engine. The higher the nitro, the more fuel cah be burned at one time. The wierd thing is, the more fuel that you pass through an engine, the cooler it runs. Thus, higher nitro should run cooler. Lower nitro means less oxygen/fuel. Lower nitro will yeild longer run times per tank but higher temps and less power because less fuel is being burned and passed through the engine.
You may notice that higher nitro fuels have lower oil content. Part of the reason for this is that higher volumes of fuel passing through means more oil passing with it.
Why can't we run 60% nitro like the boat guys? Water cooling. Once the nitro gets that high, there is less ethanol (the other 60% of the fuel's content) that both burns and helps to cool the engine by passing through in excess.
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."
In mind and body, we're all heading towards old age. It is slower to go by bike.