Guess the drag coefficient?

[Daox]

So, I'm reading through my new handy book on aerodynamics, and come across this car from 1924. Anyone care to guess the coefficient of drag?

[Stan]

That looks like Rumpler's Tropfenwagen, which in a 1979 wind tunnel test recorded a Cd of 0.28.

[Daox]

Quite right! Maybe its just me, but I find it amazing that we could develop a car that slippery 84 years ago. None of my cars I have now are more aerodynamic than this 84 year old car. Kinda makes you think.

[Stan]

Oh, I am not so surprised. Edmund Rumpler had a Ph.D. in aeronautical engineering and clearly thought a great deal about drag reduction. He was also a prolific designer, whose most famous product was the Taube of WW1 fame.



And this was his 1926 design submission for a transatlantic passenger plane.



Low-drag designing certainly did not end with him, though. In 1980 the Volkswagen ARVW registered a 0.15 Cd and went on to set numerous world speed records for diesels, ultimately setting the still-existing closed course diesel record of 362 kph (225 mph). It also got 39 mpg at 250 kph (155 mph) and 18 mpg at top speed!

[basjoos]

Here's an even earlier low Cd car, the 30 horsepower 1906 Stanley Steamer Rocket. Its body was made from an upside down wooden canoe and set a speed record of 127mph in 1906. The next year it got up to 150mph before it hit a bump in the beach sand that sent it into the air and wrecked it.