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Old 04-17-2014, 04:56 AM   #1 (permalink)
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RippinRoo - '05 Subaru Legacy Wagon 2.5 GT
90 day: 21.16 mpg (US)

Helga - '00 Volkswagen Jetta TDI
90 day: 53.91 mpg (US)

Olga - '03 Volkswagen Jetta Wagon
90 day: 46.24 mpg (US)
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VW MkIV Aerodynamic Mods (Jetta, Golf)

Thought I'd consolidate a few VW MkIV (Jetta: 1999.5 to 2005, and Golf: 1997 to 2004) aerodynamic threads since I have some interest in that subject

Actually, I could not find any good MkIV Golf threads, so I'd appreciate if others could provide links & pics. I think COcyclist has done some aero mods to his Golf, but was not able to find any related threads.

Since I'm a visual guy, I'm primarily interested in pics with descriptions of mods rather than text only.

While the aero mods are not engine-specific, the TDI seems to benefit greatly from them. The combination of some aero mods plus a taller top gear allows me to get in the 60's mpg for an entire tank (for example, ~64mpg with avg speed of ~60mph over ~975 miles a year ago; see my April 2013 entries).

An excellent starting point for aero mods on any car is the page 65+ Vehicle modifications for better fuel economy -

Onward, then, with the MkIV-specific mods, in no particular order.

** deejaaa **
User deejaaa has done some interesting stuff to his getto (Fuel Log):
- Grill block:

- Front under-panel (between bumper and skid plate):

- Rear boxing:

These are all in this thread:

Deejaaa also posted some images which could be used to sketch out some aero ideas, found in this thread:

I haven't seen any rear skirts done on a MkIV, but deejaaa is looking for ideas on how to mount a skirt in this thread:

** DIY GUY **
User DIY GUY, who is no longer active, has a Jetta TDI (Fuel Log) for which he did a pretty clean grill block:

This can be found in thread

** Deezler **
User Deezler, also no longer active, did some clean aero mods to his Bio Deezler (Fuel Log):
- Grill Block:

- Front under-body:

- Rear diffuser:

- Passenger mirror delete:

All from this thread:

Deezler also tried out vortex generators:

See this thread for more details:

** Trebuchet03 **
User trebuchet03 did some pretty in-depth flow modeling on his Jetta (which he no longer has):

The thread here has some great discussion:

Trebuchet03 also performed some aero mods on his Jetta:
- Front tire air deflector:

- Smaller driver's mirror:

Details are in this thread:

** metroschultz **
User metroschultz did some very nice bumper side vent covers and wheel covers for his daughter's car:
- Side vent covers:

- Wheel covers:

Some details are available in this thread:

** NachtRitter **
I've also done a few aero mods to Helga (Fuel Log):
- Grill block:

- Front under-body (combines with skid plate to cover nearly everything up to the firewall):

- Rear under-body (covers from axle back to the rear bumper):

- Currently working on figuring out how to mount these pizza pans to the aluminum wheels:

Unfortunately I don't yet have any build threads for my own projects.

That's all I've got for now. If you have any other MkIV aero mods, please feel free to add below!

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The Following 5 Users Say Thank You to NachtRitter For This Useful Post:
aerohead (04-19-2014), Cd (10-11-2014), ecomodded (06-24-2014), Lane_S (04-23-2014), Xist (10-10-2014)