Here is the order of hp for different fuels that I'm familiar with and this is just my opinion too, they may not be exact. I'm sure that other fuels and different types and specs come into play as well. Maybe someone has more info it would be interesting.

Nitromethane
Methanol
Ethanol
Race gas
Pump gas
Propane
Natural gas
diesel

anyone can confirm or add to this? Ps I'm just comparing fuels only.