[aerohead]

Originally Posted by kach22i

Good point.

Opinions? Duck tail vs. Carrera Tail (aerodynamically speaking) - Rennlist Discussion Forums


When Porsche first put the "ducktail" on the 911 it decreased lift and increased cooling by building up air pressure before the tail and allowing the fan to draw in more air.

Cut slot into ducktail to increase airflow into engine - Pelican Parts Technical BBS


From the above thread:

Yes,the ducktail receives the downwash off roof increasing the pressure differential across the heat exchanger(s).