Why do people own these? I mean I understand when you need to use them for power etc. But around here they are a trend thing. Like if you own a truck it has to be a diesel. Not like your pulling anything, just to say that you have one. But for example it's cold out. So people leave them running all day long. I understand some get great fuel mileage, but when you have to leave them running all the time so your fuel don't gel, then it kinda cancels each other out. Plus the fuel is more to begin with that standard gas. Seems like a lot of maintenance leaving them plugged in all the time and running all the time, just to say that you have a diesel truck.