Fuel Economy: Effect of rear spoiler on 2003 TDI Wagon?

2002_auto_tdi

Veteran Member
Joined
Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
I had a MSDesign Heckspoiler on my 03 Wagon but it had a piece missing and the clearcoat was wrecked. I decided not to repair it and took it off. When I finally got all of the silicone off, I was dismayed to find out that there were dents which it was hiding. I am reading posts here that advise MPG can actually go up with a rear spoiler and others that say it goes down.

Based on the dents, I'd "like" to do body work to make them look better or get a new spoiler but only if it does not hurt MPG AND does not look like something radical that is designed to increase fuel economy.

I don't care whether or not the fuel efficiency effect of a spoiler is negligible I just want to know whether or not a "typical" (if there is such a thing on a wagon) spoiler hurts or helps fuel economy on a wagon. I want to increase fuel economy as a hobby as I enjoy it not because I have any real need to do so. I already know about driving habits etc.

Thanks for any input.
 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
Hi

By chance do you have a picture of what the spoiler looks like on the car?

If you can make something like a kammback (sp?) Or if your spoiler is like that that would actually help MPGs .... you can read about Aero over at ecomodder

I'm also looking into doing some Aero to eke out some more MPGs. ( mainly the kammback , smaller side mirror / mirror delete , roof rack / roof rail delete , belly pans ....

I want 60 mpg at 60 mph without drafting etc.

I think spoilers can help but the angle I believe needs to be less than 15 degrees I think somewhere around 11 or 12 degrees is better...
If the angle is too steep than are separates and gets turbulent is my understanding of things...

Andrew
 
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2002_auto_tdi

Veteran Member
Joined
Aug 3, 2020
Location
Virginia
TDI
03 5spd wagon and 02 01m sedan
Hi

By chance do you have a picture of what the spoiler looks like on the car?

If you can make something like a kammback (sp?) Or if your spoiler is like that that would actually help MPGs .... you can read about Aero over at ecomodder

I'm also looking into doing some Aero to eke out some more MPGs. ( mainly the kammback , smaller side mirror / mirror delete , roof rack / roof rail delete , belly pans ....

I want 60 mpg at 60 mph without drafting etc.

Andrew
I don't actually...never took any before it broke into a thousand pieces during removal.

The kammback is a good idea and looks good but I am short on time as far as fabrication goes.
 
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