I built the truck with a fan installed. I needed weight on the electronics side to off-set battery weight so why not add a fan. Just from comments on here I thought it would be a good idea to have one on the motor. I was a little worried about speed control and motor temps but they are not really an issue with a fan. I run 10 min practice heats without issue. Granted I am not running full out crazy for that time but my set-up is working for me.