Hey, everybody. Seems like the general train of thought is that it will get better mileage but like mopar and pope say I prefer to hang my arm out and have the fresh air in my face! Never could stand being closed up with the car-or truck, in my case- shut up tight. Even run the window 1/3 way down in winter. NOT totally crazy, though. I still use heat. Thanks for everybodies thoughts on this, made for good exercise for my noodle. see ya!