Open wheel & closed wheel

[Scania]

which have better efficiency on aerodynamic?

[xpensive]

They are a world apart, all depending on this and that, but air-resistance (Cv * Cross-section Area) of a full-bodied car is perhaps half of an open-wheeled equivalent at the same speed.

[kilcoo316]

They are a world apart, all depending on this and that, but air-resistance (Cv * Cross-section Area) of a full-bodied car is perhaps half of an open-wheeled equivalent at the same speed.

Probably about right...

You can get around half the drag with a closed-wheel car.


With more floor area, you'll get more downforce with that too (area around the front wheels will contribute).

[xpensive]

I found something interesting on http://www.mulsannescorner.com, darn useful site btw, the 1969 Porsche 908 "Langheck", had a Cv of 0.345 and a cross-section area of 1.375 m^2, meaning it could reach 320 km/h with 280 Hp on the wheels.
Downforce was next to nothing though.

I doubt if today's F1 cars can do that with 700+ engine power?

In theory, the Porsche could have reached 400 km/h with 530 Hp.