On 30/06/18 18:53, Simon Jester wrote:

Cars typically put out 60 kw of heat. Even on the rare occasions
motorists stop at red lights they are still emitting 5 kw on idle.
Do we really need all this unnecessary heat?

60kW is on the high side. But that's just mechanical energy (which
eventually turns to heat). The total heat output from burning the fuel
is three times that.