Mazdaspeed rear spoiler
 

The other day, while at my friendly neighborhood Mazda dealer I got a look at the backend of a 2012 Mazdaspeed 3. It was beautiful!
http://www.drivingenthusiast.net/sec...spoiler_HR.jpg

What I couldn't help thinking was that it looked something like the spoiler talked about in this article that supposedly decreases drag by 6%: Green Car Congress: Novel Spoiler Design Reduces Fuel Consumption for Minivans, SUVs

Does anybody have any insight into whether this is the case? Is this the same or a similar spoiler? What effect does it have in real life?

We'd need to see the profile to be able to gauge the angle of departure -- to form a proper Kamm back the angle has to be down and at the correct angle. Many of these kick up, and so they usually add drag.

Here's a sideview.

http://www.automotivespecs.com/wp-co...w-pictures.jpg

Given the car's high performance, I would say that the rear spoiler is mainly for downforce at higher speeds and styling for everything else. It would not surprise me if there would be an aero penalty; drag-wise. I say that because the gap between the spoiler and the roofline is imposing (for downforce generation ?) and it does not follow a downwards trajectory; quite the opposite actually.

I could be wrong though. I will let the aero experts chime in on the matter.

Yes, I'm sure there is some added drag as a result... it's almost unavoidable. The report I read that described the development of my car's airfoil was very clear that the developers had lowered the drag to downforce/antilift ratios. However, the report was also clear that, regardless, there was still a significant increase in drag.