Well sure, that's why they use nitromethanol (which is worse in kJ/kg than gasoline, but it contains an oxidizer) and ridiculous engines. But "efficiency" in t

Well sure, that's why they use nitromethanol (which is worse in kJ/kg than gasoline, but it contains an oxidizer) and ridiculous engines. But "efficiency" in the context of engines usually means energy conversion efficiency. And power-to-weight ratio is what you mean.