I drive from Syracuse to Buffalo many times a year, and that's about a 150-ish mile trip. I've found that CC makes a large difference in my fuel economy. When I do it myself, I get ~26 MPG, and when I use CC I get ~30.
Also, not even sure if the car knows what it's talking about, but it seems to think I get better gas mileage when I open my sunroof to 'Vent'. I'm guessing it would have something to do with the increased downforce. True, it might be negligible but at 73MPH maybe it amounts to something. I would think it increases drag because of the contained vortex, at least that's what I think it's called-- my roommate is an engineer and was talking about this stuff for a week this past semester.
Regardless, no matter where I'm driving, has to be highway driving though, I get 1-2 MPG better from opening it.
Last edited by Aquinox; 06-01-2008 at 10:38 PM.
Reason: I'm an idiot.