Fuel coolers work in the most extreme cases. It removes the heat from the gas going into the tank. The Prupose of this is to keep the heat out of the fuel. If too much heat is added to the fuel, the characteristics (properties) of the fuel change. This happens because the heat in fuel will cause it to evaporate. IE methanol and nitromethane. If this occurs your essentually running a fuel with less of a percentage, therefor you need to ritchen your settings to maintain equal power causing you to use more fuel. That is why it helped the novarossi onroad guys in the hot weather to get a full 5 minutes. That worked for onroad also because those guys are traveling at a very high rate of speed. that means there was more than likely alot of air moving across that cooler which will reject more heat being benificial.
I put mine on cause it was gold....and thats the only reason. for Offroad it will have very little to no effect, unless you are the best of the best and that motor is tuned perfectly.
For me My cars come off the track and my first thought is wow that motor had a ton of power. then my pit guy shows me the temp gun at 300 eeeek!!!!
take what you will from it