Quote:
Originally Posted by MetroMPG
They increase frontal area, so there is likely an adverse effect, even if the flow normally separates/spins into a vortex at the A pillar.
I'd bet they also increase Cd, too.
If you also have them on the rear windows, they're probably also disturbing flow at the outside roof edge / C pillar.
Tuft testing will show you the extent of the disturbed flow. But I'm with Daox: I'd take 'em off!
Will it show up at the fuel pump? I'm guessing the difference is probably smaller than the normal variation you see from tank to tank (but it doesn't mean they're not hurting). |
I would guess the rear ones (if present) would act more as a parachute based on the picture... so those should come off. The front ones are debatable... it will probably come down to how much use you get out of having them.