STi

Hmm looks like I posted in the wrong forum before...

Does anyone know the coefficient of drag of this car?

Thanks.

NightRider

Funny enough, it is the same coefficient of drag as a Corvette which I believe is .26

Tread

more like 0.29 for the TL, not class leading, but good still

NightRider

I have heard this quote about having the same c of d as a corvette from several people on here, who's car in the near luxury sedan class is more aerodynamic than a Corvette? Let alone our car. When I was looking at a G35 I belive those are .30

Aspector Gadget

0.29 is correct and with the a-spec kit it actually goes down to 0.28. And here is my source:

http://www.autoweek.com/search/searc...00726&record=1

STi

G35 and TSX are both around 0.26 I believe. Keep in mind that the actual drag force is lower with the TSX even though they have the same Cd, because of the smaller frontal area.

Thanks for the replies guys.

texas_acura

Frontal area is only a small part of the equation...

TSX is 0.27 as is a G35. A G35 with a spoiler is 0.26. TL is 0.29, but I read somewhere recently that its one of the lowest in the class.

1SICKLEX

I think G35 may get to .26 with the optional Aero Kit only. Then its a .27 which is pretty damn slippery. The LS 430 is a .26, which is incredible for such a huge car.

The Vette is very slippery but sacrificed some styling b/c that flat rear helps tons.

dsc888

One quick question guys...Am I right to assume that you only get the .28 with the FULL A-Spec package including the lowered suspension. Many of us including myself only have the underspoiler and the lip spoiler. I imagine that ride height plays into the cd as well. Can someone enlighten me on this topic. thanks.

dsc888

NightRider

In reality I don't know if in let's say, 2 quarter mile runs with the same car, that c of d of .30 or .26 is noticably beneficial to performance.

birdboy

can someone explain this spec? would it have something to do with the way the car is shaped and how wind resistance reacts to it?

need4spd

For this, not only is Cd important, but the frontal area also has a play in 1/4 mile runs and resistance.

Don't play too much into Cd changes of 0.01 - 0.02, in the real world it is not noticable.

youngTL

It is, however, noticably beneficial to fuel economy on a long highway trip at increased speeds. As I'm sure you know, as you increase your speed, the drag force increases exponentially. Over a long period of time, you would notice a considerable difference in fuel economy. But that's right it probably wouldn't help you much in a run.

Xpditor

The TL in stock form coefficient of drag is .29. That is exactly the same as the Corvette's: .29. The new 2005 Corvette improves that slightly to about .285.

Source: www.corvette.com - specs.

And, actually, it IS class leading. I don't know of another sport-luxury sedan that is more slippery.

The LS430, although not a sport-luxury, is even more impressive at .26.

XP

Xpditor

The "actual drag force" includes the frontal area in the calculation. The drag of the car is the drag of the car- all things considered. The frontal area contributes to that drag factor.

As to the G35 and TSX being .26, they are not. The G35 COUPE is .29 and the aero package brings it done to .28 like the A-Spec SEDAN.

Not sure about the TSX. I'll have to check but I don't remember that it is lower than the TL. I'll get back to you.

XP

Xpditor

Yes. It absolutely has a lot to do with the way the car is shaped and the attention to things like outside mirrors and the undercarriage. The shape of the nose is important, but so is the shape of the rear end. Door handles and antennae also affect Cd.

If you look at the underside of the TL in front, you will see an air dam below the bumper and other panels to smooth the flow of air under the car. Tires and wheels are also a consideration. It takes a lot of testing in wind tunnels to get a car down to .29 or less. It doesn't matter how heavy the car is nor how long. Actually, longer sometimes helps the Cd as it straightens the flow around the car body and lets it exit without a lot of turbulance. As an example, a fairly big car like a Lexus LS430 has less drag than many sports cars (even its own). Lexus spent the time in the wind tunnel and tuned everything from door handles to wheels and trim and it paid off.

XP

geminis2

The A-spec add on kit lowers drag??

EZZ

It is NOT class leading. The G35 sedan is 0.27 without aero package. 0.26 with aero package. I can't let misinformation slide

Xpditor

I only listed the COUPE Cd as I did not have the figures for the sedan.

If accurate, thanks for the info. I did say that I didn't know of one more slick. Interesting that the sedan has a lower Cd than the COUPE. But, this is often the case. I wonder what the VW Phaeton is?

XP

EZZ

Just busting your balls The coupe is also heavier. I guess the price you pay for beauty cause the sedan is pretty ugly (IMO).

Nicki

What is the lowest drag coefficient possible with an automobile, and what car is it? Year make model...

Xpditor

STi,

You are entirely correct. I misread your post the first time.

The CD is a ratio of the 2 dimensional frontal area (flat board) theoretical drag vs. the actual 3 dimensional (shaped) drag. The result is a factor (CD) that needs to be multiplied by the frontal area to get the actual drag force.

Implied in this: a larger car with a lower CD can have more "wind resistance" than a smaller car with a higher CD.

I could go into this in more detail if anyone is interested in the math.

Sorry about the misunderstanding. :o

XP

Xpditor

The typical modern automobile achieves a drag coefficient of between 0.30 and 0.35.
SUV's, with their larger, flatter shapes, typically achieve a Cd of 0.35-0.45.

Sports cars can achieve figures of 0.25-0.30, although sometimes designers deliberately
compromise drag in favor of reducing lift.

The Mini convertible has a coefficient of drag of 0.37.

Present day ‘Stock Cars’ have managed to achieve a “cee-dee-alpha” (coefficient of drag)
of less than 0.30 – typically 0.25.

A runner has a CD about 0.5, a racing bicyclist about 0.4. An airfoil shape used on aircraft wings or rotor blades, typically has an extremely small CD about 0.04.

I would suspect the lowest CD on autos would be for super-streamlined Bonneville Salt Flat top speed contenders. Long, cylindrical with a basic tear shape on its side with the pointy end in the back. The exit shape is as important as the entry shape.

A falling drop of water is a free form which takes its shape from the path through the air of least resistance. Falling drop of water in a vacuum is perfectly round.

Am I putting you to sleep? Anyone? Anyone? Bueller?

XP