Up here in alaska are average temperature is about 70deg and the smooth can neu's run cool as a cucumber. Right know I'm running a 40mm cooling fan on a smooth 1515 2d (2050kv) on 4s (30,000 rpm's) in a 9 pound ofna violator 9.5 buggy with truggy wheels and komodo low pro's...after 25 minutes of thrashing my motor temps are only 105deg my mm control is 115 and my polyquest pack is at 90deg all super low temps.