1921 Rumpler Tropfenwagen sedan - photo

[Toolmaker51]

-Yup, but you can't get a CdA @ 0,28 just for free - as it was the world's first aero-dynamically designed auto.
Its 2.6 L Siemens & Halske (sic!) engine of 36 hp pulled the 3000 lb car up to 70 mph a hundred years ago...

No early April joke here, check for yourselves:
https://en.wikipedia.org/wiki/Automo...ag_coefficient
https://en.wikipedia.org/wiki/Rumpler_Tropfenwagen
https://www.carfolio.com/rumpler-tropfenwagen-98219

Cheers
Johan

3000 pounds at 70 mph? I don't see adequate brakes, can't judge suspension; but the Autobahn wasn't known for bad paving.

CdA was unfamiliar abbreviation for drag coefficient, we use B.C. (and BC interchangeably) in ballistics; so I rang up https://en.wikipedia.org/wiki/Drag_coefficient.