It's a Drag: Most Cars Today Are Not As Aerodynamic As a 1921 Rumpler
by Lloyd Alter, Toronto on 07.23.08
In 1921 Edmund Rumpler wowed the Berlin Auto Show with the Teardrop. The engine components were enclosed in a tub underneath, and from the top it had a teardrop shape. The public thought it was ugly, it was hard to steer, there was no trunk space and it evidently was "outrageously expensive." Thinking it looked futuristic, Fritz Lang bought then at deep discount and blew them all up in his movie Metropolis.
In 1979, Volkswagen took one of the two remaining cars and put it in its wind tunnel. They found that it had a drag coefficent (CD value) of only 0.28, better than any car on the market at the time. Today it is still better than most of the cars on the market. ::Club of Pioneers
Rumpler front via Jalopnik
Make your own Rumpler! Slightly larger original here
The Toyota Prius beats it with a 0.26 CD, but interestingly, the lowest CD of any car produced since the Teardrop is the now-squished General Motors EV-1, with a CD of 0.195. The Aptera is projected to come in at 0.11, a new record. See a table of CDs at ::Wikipedia
See also ::Wheelspin
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Moral of story? Aerodynamic cars get destroyed, not driven?
Is there any charts with fuel savings at higher drag coefficients? I've read that most of the fuel is used to push the car through the air at speeds over 40mph.
The formula for drag is
D=0.5*Cd*rho*A*V^2
Where
D= dimensional drag
Cd= drag coefficient
rho=density of the fluid
A= reference area (usually frontal area or surface area)
V=velocity
Drag is proportional to velocity squared. Power and thus fuel consumption is proportional to drag times velocity. So fuel consumption is proportional to velocity cubed so the curve of speed vs fuel consumption goes up pretty quickly.
This article is a bit misleading because lower drag coefficient does not necessarily mean lower drag. It depends on the area used which either way is much higher than the area for a Prius.
See this piece here on drag area
http://en.wikipedia.org/wiki/Automobile_drag_coefficient