I'm interested to learn what percentage MPG loss/increase there is to each speed. (this has made me wonder for a while since MetroMPG got a 2.3% MPG increase when removing mirrors @ 55mph in mild temperatures, while I got a 2.23% increase when driving 70mph in really cold temperatures, without mirrors).
EDIT: Did you put the mirror back on? Or is that an older pic?
20% was a good guess... for 40mph . Take a look at the video and see the difference for yourself.
BTW, I've had the mirrors back on the Geo for weeks now. The plastic covers for the holes in the door froze and fell off and it looked dumb. I'll make better plastic covers when the weather gets a bit nicer.
Edit: *gasp* I forgot to put the gassavers link on the video
Those are huge numbers for something as simple as opening up the rear hatch. What do you think my Cd was when it was open? 0.44? I'm now beginning to believe that small aero mods to these little cars (such as mirror removal, wheel skirts, etc) would help FE in more than just highway travel.
At 25-30 mph or so is when aero losses become as large as rolling losses on flat ground. So even at those speeds, aero mods should in theory have significance. But this is steady speed driving as opposed to stop and go driving. Stop and godriving will make weight and rolling losses a much larger factor than they are in steady speed driving.