Hi,
I'm getting ready to order a 2009 Jetta SportWagen TDI and one of the options I'm considering is the Roof Edge Spoiler. My question is does the roof edge spoiler really help the aerodynamics? Or does it just add downforce, not a bad thing. What I don't want is to create drag to look cool, think of those huge aftermarket rear wings that just create a lot of drag and reduce top speed.
My daily driver is a lightly modified 1987 Merkur XR4Ti, it has a biplane spoiler and Ford did a lot of windtunnel work with the spoiler to reduce drag. No additional downforce unless you get a Cosworth whaletail spoiler.
I'm willing to pay the $356 for better fuel economy, but it would kill me if I paid for a spoiler that creates drag and higher diesel consumption.
The Volkswagen website just has the tonge in cheek "The wind tunnel tested roof edge spoiler is proven to give the Jetta SportWagen better aerodynamics and the owner more dates."
Anybody know if there is any real data out there.

Thanks

 

i doubt it does anything at all, cause IF it does work spoilers only start to give more downforce at like 100mph so i wouldnt waist the money, it is mostly for looks

 

The Spoiler does the trick of keeping your rear hatch window from getting covered with dirt! I own a 2004 Jetta Wagon and bought a Spoiler 2 years after always getting covered with road dust and dirt. The drag point comes across the top of the wagon and down the back. I do alot of highway travel and can wash the car, go down the highway 10 miles or so and if there is ANY construction or dusty conditions, my rear window used to get covered. I spent more money on windshield washer fluid and washing my clothes from rubbing up against the hatchback when opening. I spent $185.00 on an aftermarket spoiler and had my son paint it with some paint I had left from a small fender dent. IS it worth it? I say YES, DO IT now! The paint will match perfect and it REALLY looks nice on the back end! Unless you like washing your rear window all the time or having the wiper do the cleaning all the time.

 

I had not thought about the dirt on the rear window. I do not want some silly wing just for looks, but a clean rear window is a good thing. I will get the roof edge spoiler.
The Merkur's spoiler does not really deliver any downforce. It is a shame downforce would be helpful in the XR4Ti, it is a rear wheel drive. I do not plan on driving the Sportwagen at high speed so downforce is not an issue, just highway speed drag. I do like the VW website giving the TDI a 1 mph greater top speed than the gas cars.