Drag Coefficient?

[Seinster]

Does anybody know of the drag coefficient of the XD, and XD2?
I can't find it anywhere...
Please help.

Thanks,
Mark

[WytchDctr]

MSN some time ago had it at 0.32, but they dropped that section of there car info. That was an XD.

[jayupark]

http://www.economist.com.na/2001/100501/story21.htm

.33 is VERY impressive... Look at some of the cars in that range (same as the Audi A3 and Impreza STI)

# 0.372 - Ferrari F50, 1996
# 0.36 - Eagle Talon, mid-1990s
# 0.36 - Citroën DS, 1955
# 0.36 - Ferrari Testarossa, 1986
# 0.36 - Opel GT, 1969
# 0.36 - Honda Civic, 2001
# 0.36 - Citroën CX, 1974 (the car was named after the term for drag coefficient)
# 0.355 - NSU Ro 80, 1967
# 0.34 - Ford Sierra, 1982
# 0.34 - Ferrari F40, 1987
# 0.34 - Chevrolet Caprice, 1994-1996
# 0.34 - Chevrolet Corvette Z06, 2006
# 0.338 - Chevrolet Camaro, 1995
# 0.33 - Dodge Charger, 2006
# 0.33 - Audi A3, 2006
# 0.33 - Subaru Impreza WRX STi, 2004
# 0.33 - Mazda RX-7 FC3C, 1987-91
# 0.33 - Citroen SM, 1970
# 0.32064 - Volkswagen GTI Mk V, 2006 (0.3216 with ground effects)
# 0.32 - Toyota Celica,1995-2005
# 0.31 - Citroën GS, 1970
# 0.31 - Renault 25, 1984
# 0.31 - Citroën AX, 1986
# 0.31 - Mazda RX-7 FC3S, 1986-91
# 0.31 - Eagle Vision
# 0.30 - Saab 92, 1947
# 0.30 - Audi 100, 1983
# 0.30 - Porsche 996, 1997
# 0.30 - BMW E90, 2006
# 0.29 - Porsche Boxster, 2005
# 0.29 - Chevrolet Corvette, 2005

[g35doc]

G35 coupe is 0.29 (0.28 w/ aero package). 0.01 lower than the 350Z. Is there anything with 0.27?

[WytchDctr]

http://www.insightcentral.net/encyclopedia/enaero.html

Insight 0.25

[CTele02]

I wonder if my tiny corner kia lip kit helps with the drag coefficient lol... it adds about 1.5inches of drop on each front corner..

Heres a thread from way back talkin about drag with the evo mr and its "vortex generators" http://www.elantraxd.com/forums/showthread.php?t=4326&page=1&pp=20

Also what about lowering our cars? How much does lowering a car have on its drag?

Well heres some basics on drag (mostly about airplanes): http://www.grc.nasa.gov/WWW/K-12/airplane/dragco.html

http://en.wikipedia.org/wiki/Drag_coefficient
The drag coefficient is a common metric in automotive design, where designers strive to achieve a low coefficient. Minimizing drag is done to improve fuel efficiency at highway speeds, where aerodynamic effects represent a substantial fraction of the energy needed to keep the car moving. Indeed, aerodynamic drag increases with the square of speed. Aerodynamics are also of increasing concern to truck designers, where a lower drag coefficient translates directly into lower fuel costs.

About 60% of the power required to cruise at highway speeds is taken up overcoming air drag, and this increases very quickly at high speed. Therefore, a vehicle with substantially better aerodynamics will be much more fuel efficient.

"The typical modern automobile achieves a drag coefficient of between 0.30 and 0.35. SUVs, with their flatter shapes, typically achieve a Cd of 0.35–0.45. Notably, certain cars can achieve figures of 0.25-0.30, although sometimes designers deliberately increase drag in order to reduce lift."

Lower Drag Coefficient = more lift.

Lowest Drag of any modern "production" vehicle:
0.195 - General Motors EV1, 1996 :)

[SWortham]

The new Legacy GT has a very good coefficient of drag for a sedan at 0.28. And I think it was a certain variant of the C5 Corvette that had a Cd of 0.25. But 0.33 is not bad.

Lower Drag Coefficient = more lift.
Well that's certainly not a hard and fast rule. One of the flaws in most car designs is still a lack of concern for aerodynamics underneath the car. But if a car is designed with underbody paneling, then it can achieve both less lift and a lower coefficient of drag than a car without. Lamborghini is one manufacturer that builds full underbody paneling for their cars. And it's becoming more and more common for some of the sporty/high-end cars to have some partial underbody paneling & diffusers.

By the way, if you want to improve the Cd of the XD while also reducing lift then look into getting a Mach 1 front lip spoiler like Only1db has. I'm pretty sure it'll do both.

[CTele02]

Well I did the corner lip kit mostly for looks and since the XD2's lower bumper is different than the XD's lower bumper.

[Seinster]

Thanks for the help.

[LateAPXR]

I'd be interested in how lowering the car helps. After the Ksports my car was set about 2.5 inches lower (I think...I'm at 23 3/4" all around...so whatever stock is minus that) and I noticed an increase in gas mileage.

[SWortham]

I'd be interested in how lowering the car helps.
Me too. I know that it should help, especially if you rake the front. Whenever you can it's good reduce the amount of air going underneath the aerodynamically-challenged underside of the car.

[CTele02]

So a body kit/lip kit and lowering springs should reduce the amount of air flowing under the car... As long as the kit flows smoothly it should in fact reduce drag.