The other is, given I'm going to own a car already, what's the difference between a shorter commute and a longer one? That's going to be a lower number per mile. A big chunk of the vehicle's depreciation is a result of years rather than miles, insurance doesn't generally track how many miles you drive and charge extra if you drive more, the registration and tax isn't any different etc.
The second one is how a lot of people end up all the way out in the suburbs. They can't afford to live in the part of the city that makes it viable to not have a car at all, but once you have a car as a sunk cost, another ten or twenty (or thirty or ...) miles in exchange for saving hundreds of thousands of dollars on housing starts to look like a good deal.
Though the huge factor people commonly forget is their own time. If your time is worth $25/hour then a half hour each way on your commute is $6500/year. And that's assuming you're only further away from work and not also further away from whatever you do on weekends.