Windows, gas mileage, and the hatch

[Chuck McKnight]

I tend to like to drive with the Vibe totally opened up—all four windows and the moon roof.However, I can't help but wonder if that's sucking away my gas mileage. I mean, I'm basically creating this giant pocket in the back to suck in air and create drag. Anyone know for sure if my thinking is accurate, and any idea just how much gas I'm losing this way (especially considering that I usually drive like this at highway speeds)?Well, all that got me thinking about that rear hatch window. If I could just open that up, it should take care of most of the problem. But I'm guessing it would not be a very smart idea to just drive with it open? Has anyone tried it?What about creative ways to open up that area or otherwise reduce the drag?

[journeyforce]

I would be interested in knowing this alsoYou actually get better gas mileage at highway speeds with the air condition on then with all windows down because at 50mph + you start to encounter a lot of wind resistanceI always drive(when applicable) with the windows open under highway speeds or start and stop traffic and use the A/C when driving highway speedsI was told that the best way to utilize the sunroof for air flow and wind noise is to open the rear windows a few inches when the sunroof is open so you get good air flow and the air can escapeI don't know how safe opening the rear window would be with the hinges on older wagons and SUV, you could roll the rear window down but now a days it is hinges

[Beer Belly]

I've driven with the glass open, bringing home 12 to 14ft pieces of lumber and wood trim. I've never had a problem, the glass doesn't bounce up and down. I've never really hit a hard bump with it open either, i'd be afraid of it slamming down and shattering.