Will this spoiler help or hurt my mileage?

[C3Killer]

I was looking on the swift forum before I was shown the wonderful world of ecomodder, and posted a listing for one of these spoilers..... http://redlinegti.com/images/vic04.23.jpg Question is, will this help or hurt my mileage? Right now I have a '94 Metro with nothing, no rear wiper even. Thanks. C3.

For those of you curious to see if I have finished my other skirt, I am working on it tonight!

[NeilBlanchard]

Hello,

The OP is not asking about downforce; but about improving aerodynamics or not. I have a similar small (and flat) extension on the back edge of the roof. I think the affect one way or the other is practically nil.

It keeps snow and rain from hitting the top of the window. Other than that, it is a visual thing. It could have some small affect, but I don't think it does.

Further comment on the disparaging comment above: all cars can be affected (good or bad) by aerodynamics -- it affects the handling and stability. Short of a wing of a COT or a F1, there are no street cars that need downforce to help get the power on the ground...

[Tourigjm]

it would cause separation of the airflow over the rear of your vehicle. the resulting vorticies would be larger than without the spoiler, the angle the airflow would have to follow in order to attain attached flow would be even greater. basicly you get more drag and less MPG, check out what MetroMPG is doing with his kammback on his metro

[C3Killer]

Yeah, I have been following MetroMPG's thread for some time. But I was actually thinking of this thread..... Hatch Wing on 2009 Toyota Matrix

The 11th post down. So concensus is it will hurt my mileage........ Thats what I thought.