[MetroMPG]

Reviving this thread...

I've finally got some photos/video of tuft testing my dad's Corolla with & without the Airtabs.

I'll just say that the difference is pretty dramatic. It's not a case of "well, it looks like there might be a little less turbulence on the rear window" - it's plain as day that the tufts on the glass & trunk lid behave themselves much better with the airtabs on the roof.

SO... why then didn't they appear to make any difference to MPG? Can the energy going into vortex creation be largely cancelling out their aerodynamic benefits apparently seen on the rear glass?

It's worth repeating that I did think there was an audible difference with the VG's on the roof (louder). If I had something I could use to easily measure noise levels, I'd test that too.

Will post the pictures later.