this is the thing, you tune your engine for its normal fulltime performance, like as in you dont risk overleaning and killing it when your just driving around... but then you have that bottle of nitro somewhere in your car, and with an extra channel on your radio(for instance if your not using reverse) you can give a shot of nitro that boosts the engine's performance, since its only running like that for a few seconds , wear shouldnt be a problem, i dont know if an engine can even have time to heat up to the temperatures that you get when you set the needles too lean... think of it as something like on the fly fuel leaning