As the title said, is it a waste of time, or an excuse to get lower emission figures??? the reason I ask is what good is a system that doesn't operate when the heater is set below 17 degrees, in the summer when you have no electrical equipment on it doesn't operate but in the winter when you have the possibility to have the heater fan on full ,heated front screen on heated rear screen on, wipers on, heated seats on, lights on. why would you want to put extra drain on the battery starting the engine ???? surly it should be the other way round, and yes I do know if there is too much drain on the battery it doesn't work either, another reason it is useless. as an addition to the above all turbo engines should be allowed to idle for a couple of minutes before turning off the engine. ( it tells you this in the manual) The reason for this is to let the turbo cool so that the oil in the turbo bearings doesn't burn off leaving the bearings dry causing wear on start up, and premature turbo failure. so what happens when start stop operates? yup as soon as you finish your journey,The engine stops and the turbo is still at operating temp, very clever . so what do you think??