My dad just told me that he was told that you are no longer supposed to start your vehicle to let it warm up (before driving it). I have always started my vehicle in the winter and let it run for about 10 minutes. I thought it was to get all the juices (gas, oil, lube) running in the motor before making the motor run. He said it was something about the gas and the poor quality of it that you were not supposed to start early anymore? Fuel injection or something like this? Anyone hear anything like this? Does it make any sense to you?