Mystery aero-device on Audi S5? - Fuelly Forums
Go Back   Fuelly Forums > Fuel Talk > Aerodynamics
Search Today's Posts Mark Forums Read
Thread Tools Display Modes
Old 01-25-2008, 04:10 PM   #1
Registered Member
SL8Brick's Avatar
Join Date: Jun 2007
Posts: 180
Country: United States
Mystery aero-device on Audi S5?

I was checking out a few S5s on our dealership lot and couldn't help noticing this unusual aluminum-colored thing a the bottom of the rear bumper, between the tailpipes:

It may look small in the photo, but it protrudes a good 3" from the bumper surface. Is this just flashy eye-candy or does it have potential function as a lower level difusor/extension?

1993 Volvo 240 Wagon - 323k miles (awaiting recommissioning)
1999 Audi A6 Avant Quattro - 149k miles(the NEW daily driver)
SL8Brick is offline   Reply With Quote
Old 01-26-2008, 04:19 AM   #2
Registered Member
GasSavers_TomO's Avatar
Join Date: Oct 2006
Posts: 1,108
Country: United States
Send a message via AIM to GasSavers_TomO Send a message via MSN to GasSavers_TomO Send a message via Yahoo to GasSavers_TomO
My guess would be partial eye candy with a small benefit similar to a diffuser.


Honda Civic VX Info/Links
Remember to use good Webiquette!
Originally Posted by ezeedee View Post
controversy is an idea thought up by weak people who are too afraid to hear the truth.
GasSavers_TomO is offline   Reply With Quote
Old 01-26-2008, 12:58 PM   #3
Registered Member
Snax's Avatar
Join Date: Mar 2007
Posts: 758
Country: United States
My guess is that the rounded profile of the bumper encouraged air to follow it too high up from underneath. The lip encourages immediate seperation.

I think, therefore I doubt.
Snax is offline   Reply With Quote
Old 01-27-2008, 08:53 AM   #4
Registered Member
lunarhighway's Avatar
Join Date: Dec 2006
Posts: 360
Country: United States
the devise (and the car) pictured above looks more subtle and stylish than what i'll show below
my kadett (also note the massive pop up whale tail spoiler )

here's another example on a citroen AX

both cars have a very prominent "lip" on the rear bumper... i suppose this is somewhat similar to the lip spoilers found on the rooflines of hatchbacks and sometimes trunklids on sedans... just something to get the air off in the right direction like Snax pointed out... note that the AX has a spoiler like portrusion at the base of the windshield... this was part of the trunklid and all models had this... i believe the cd of the car was around 0.32 wich is pretty good for something build in the 80's... it's interesing as the angle of the windhield would not allow the air to stay attached , but maybe the bump breaks some turbulence going on there. anyway, i just mention it as these are two cars that had a lot of aerodynamic features for the time, so i'm sure these bumps and lips are there for a reason other than looks...

the audi looks great, and is probably much more aerodynamic too, but on todays smooth styled cars it's sometimes hard to tell what's for looks and what's effective

lunarhighway is offline   Reply With Quote
Old 01-27-2008, 11:13 AM   #5
Registered Member
brucepick's Avatar
Join Date: Feb 2007
Posts: 722
Country: United States
Location: Connecticut
Yes - I've seen similar on most Lexuses (Lexi??), though in painted plastic.
I think it must be to encourage clean separation.
Or you could call it a mini-mini Kamm back. Same idea either way, I'd think.
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.

Now driving '97 Civic HX; tires ~ 50 psi. '89 Volvo 240 = semi-retired.
brucepick is offline   Reply With Quote
Old 01-27-2008, 11:15 AM   #6
Registered Member
JanGeo's Avatar
Join Date: Jan 2006
Posts: 2,442
Country: United States
Send a message via Yahoo to JanGeo
It may also prevent exhaust fumes from building up around the trunk and may also create a vortex around the pipes. Sure wasn't put there by accident . . . that's for sure!
JanGeo is offline   Reply With Quote
Old 01-28-2008, 02:24 AM   #7
Registered Member
DarbyWalters's Avatar
Join Date: Oct 2007
Posts: 376
Country: United States
Seems like an easy addition to almost any vehicle!
2006 Jeep Liberty CRD...Founder of L.O.S.T.
OME 2.25" Lift w/ Toyo Open Country HTs 235/75/16s
ASFIR Alum Eng/Tranny/Transfercase/Fuel Skids
2002 Air Box Mod...Air Tabs (5) on Roof...(3)each behind rear windows
Partial Grill Block with Custom Air Scoop and 3" Open Catback Exhaust
Lambretta UNO150cc 4 Stroke Scooter

DarbyWalters is offline   Reply With Quote
Old 01-28-2008, 02:42 AM   #8
Registered Member
GasSavers_SD26's Avatar
Join Date: Dec 2007
Posts: 529
Country: United States
I think it looks cool.

GasSavers_SD26 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Incorrect Milage Calcuatlion PatM Fuelly Web Support and Community News 4 07-17-2009 07:21 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -8. The time now is 02:43 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.