Not true, we tested a 4 and 6" cowl on the same car against a HEMI scoop. The cowl was actually faster every time. I catches the air from the windshield, and lots of it.
I would agree with that. Don't think that they don't pickup air. I watch the cowl hood on the Demon lift up all the time down track so they must pull a heck of a lot of air off the windshield.
