Mercedes-Benz reportedly shooting for .20 Cd production car in next five years
2010 Mercedes-Benz E-Class Coupe - Click above for a hi-res gallery
In a previous post from AutoblogGreen's Greenlings series, we took a brief look at how and why aerodynamics play a significant role in a vehicle's overall efficiency. To put in plainly, the easier a car is to push through the wind, the better its fuel efficiency is likely to be. Mercedes-Benz has made great strides in overall vehicle aerodynamics with its new 2010 E-Class Coupe, which boasts an impressive .24 coefficient of drag. According to that car's project manager Rainer Tiefenbacher, the best is yet to come:
"There is still plenty more to come as we explore ways of improving fuel efficiency. Designers are still learning about what works aerodynamically and are having to consider it more and more when they think about how a car will look. There are big steps to be made, especially around and under the engine hood."Just how low could they go? Very low indeed, it would seem – the German automaker believes it will be selling cars with a Cd of less than .20 in just five years.
Gallery: 2010 Mercedes-Benz E-Class Coupe
[Source: Autocar]
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Reader Comments (Page 1 of 2)
Patrick 11:06AM (4/30/2009)
That means they will have to minimize frontal area, which is in direct opposition to their current design trend of making tall front ends and European pedestrian safety standards. Good luck.
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MikeW 11:18AM (4/30/2009)
Not really. Coefficient is independent of swept area.
If anything a larger swept area would give the aerodynamicist more leeway as to finding the least restrictive way to route the air.
Serge 11:14AM (4/30/2009)
While that may be the "easiest" way to minimize drag... I don't think that's what MB meant to say.
.24 is a really low drag coefficient, yet the car still has a "tall" front end. Aerodynamics are tricky that way, you'd think a Lambo Countach would be aerodynamic... but it really isn't.
elpyrodude 11:15AM (4/30/2009)
frontal area is multiplied by the Cd to give total drag (which is the number that in the end will affect fuel economy), but if they can get the same general size to be slipperier through the air and not have it look like a tear drop like an old ford probe concept car, that would be excellent
Ligor 12:31PM (4/30/2009)
@ elpyrodude
it's not the frontal area that's multiplied
it's the cross-sectional area if you look at the car head-on
so you make the biggest 'rectangle' as you look at it head on, which has nothing to do with the grille
this just puts Toyota's Prius to shame with teh 0.25 coefficient of drag they have - adn this look about 10000x better. so here is another way Toyota's ideas are challenged and the crap they put out in engineering needs not be followed by anyone. kinda of like Honda did with the ne Insight.
If you have cash and spend it in the wind tunnel you'll be able to get drag coeficients less than that of the prius and come out with a beautiful desing
thank god they proved them worn as I was fearing we'd have
more Prius-UGLY-look-a-likes that I ever want to see
why not the LS2LS7? 12:41PM (4/30/2009)
Ligor:
It's the frontal area that's multiplied.
blogee9 12:42PM (4/30/2009)
"That means they will have to minimize frontal area, which is in direct opposition to their current design trend of making tall front ends and European pedestrian safety standards. Good luck."
Minimizing FRONTAL AREA means lowering the roof and/or making the car narrower, because FRONTAL AREA is a projected image of a whole car from the front.
Tall front end has nothing to do with FRONTAL AREA.
Jake B 2:05PM (4/30/2009)
Yeah you have to multiply Cd by the cross sectional area, the roof and such have to be taken into account, not just the front end. Otherwise you could just have a two story cab on top of a go cart and it not be a big deal for aerodynamics, yeah right.
Brandon 3:03PM (4/30/2009)
@why not the LS2LS7
frontal area to cross section area ratio would change the Cd, but it's the cross section area that gets multiplied to Cd. Bigger frontal area = bigger Cd (most likely)
why not the LS2LS7? 7:59PM (4/30/2009)
Frontal area is what you call cross-sectional area.
http://en.wikipedia.org/wiki/Drag_equation
People call it the projected cross section area or whatever, that's fine.
But those who get confused and think frontal area has only do do with what's at the front end of the car are on the wrong track. The frontal area is the total area of the car as projected onto a plane directly in front of it in the direction of travel.
f1tifoso 11:49PM (5/01/2009)
for patty the irish twit:
Actually the ideal low drag shape HAS a large front that tapers off at the rear -
didn't think that comment through much did you...
carcomptoy 11:16AM (4/30/2009)
Well, considering that the relatively regularly styled E-class coupe has a .24 Cd, I don't think .20 is that farfetched. To be honest, I'm pretty impressed. I that those numbers could only be obtained with a Prius shape.
Other manufacturers should step up with low Cd numbers on their cars as well!
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Auari 11:20AM (4/30/2009)
ya that would be funny, instead of saying my car get 30 MPG, now people are saying Ya my car is .24cd BEAT THAT!
Serge 11:22AM (4/30/2009)
Let the Cd wars begin!!!
Quattroporte 12:27PM (4/30/2009)
"Let the Cd wars begin!!!"
BMW 6-Series .300
Audi S5 .306
The Bavarians have some work to do.
http://www.carfolio.com/specifications/
Kitko 12:41PM (4/30/2009)
JDM and Euro Mazda6 sedan and lifback models have Cd 0.27, lowest in the class. Estate has 0.28.
A production Tatra T77 from 1935 had Cd 0.212.
http://en.wikipedia.org/wiki/Automobile_drag_coefficients
(you can arrange the table according to the Cd levels)
Serge 11:21AM (4/30/2009)
The new E-class looks really good in person, especially the coupe. I was amazed when I saw a solid red E550 Coupe at the NY Auto Show (I think it was a 550?)... the sedan is also considerably better looking than it is in person.
I'm still disappointed about the interior though... I don't like the straight-line-cut 80's dash and console... doesn't look upscale, especially without leather.
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Serge 11:23AM (4/30/2009)
"the sedan is also considerably better looking than it is in person."
I don't even know what I said there... working to hard!
what I meant was: The sedan is considerably better looking in person than in pictures as well.
timurjonchik 11:28AM (4/30/2009)
So UGLY
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Serge 11:53AM (4/30/2009)
I know dude... we all feel bad for you :'(