I asked this question a few weeks ago and got some good answers but no one
answered my original question: Why the roof spoiler is there (E46. Maybe
others?). So, does anyone know why the engineers at BMW have added this
feature? Seems to me that a smooth roof-line would create the best flow of
air over that part of the body. I understand the theory and usefulness of
the front air dam, side-skirts and rear deck spoiler. TIA!
IIRC the theory behind roof spoilers is that the downforce is applied to
the balance centre of the car, so if the car is nicely balanced then you
get equal downforce at both ends.
It's all cobblers, of course, since unless you're on a race track and
doing about 150 mph, it's going to make bog-all difference to the
handling. You could try removing it and seeing what happens. If you
immediately crash, I was wrong.
BMW 740iL - Stately progress for the mature gentleman
And what has that got to do with my comment?
I also think your explanation of their purpose is incorrect.
AIUI they are intended to reduce drag, rather than contribute any downforce.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.