Quote:
Originally Posted by Topless
Quite the opposite actually. Instead of creating downforce our spoiler "spoils" lift and often but not always reduces Cd. Airflow lifting several hundred lbs on the tail of the car causes a low pressure zone, turbulence and drag. Solve that and you improve stability, fuel efficiency, and straight line speed. Porsche aerodynamicists understand this, tested and confirmed it. Some grasshoppers not so much. 
The modern 991 Turbo takes it a step further with active front and rear spoilers but the goal is the same. Stability, fuel efficiency and straight line speed with the lowest possible Cd. https://www.youtube.com/watch?v=A9FluxQn0ZE |
First of all, drop the name calling.
Secondly, why doesn't Porsche just leave the spoiler in the up position all the time on our Boxster? If it increases fuel economy, aids in less drag and they could reduce cost and weight to the car by leaving the spoiler motor out.
The answer is Porsche knows it does not aid in fuel consumption nor reduce drag on the car. It's only deployed at the speed Porsche feels the car needs the added downforce.