fender/hood extractors: helps or hurts?
 

Aerodynamic Tips Tricks Extractors Photo 6

i'm guessing not really helpful...

Check out the following thread.

http://ecomodder.com/forum/showthrea...rs-4927-2.html

extractors
 

I'm not current with respect to state-of-the-art aero,but in the past 90-years,the extractors were never included in a drag reduction application.
They always had something to do with lift issues.
Some of the faster muscle cars of today are using the extractors to mitigate front lift between 150,and 200-mph.So it may remain a high-speed stability tool rather than an economy trick.