That is surprising. On the other hand, the drag coefficient is a measure of the drag per unit of surface area at any given speed and the F1 car has much less surface area than the Hummer. I am still surprised that the Hummer does so well compared to F1, especially since the coefficient is multiplied by the surface area and the square of the velocity. So, if you double the speed of a car, its drag goes up by a factor of 4. How fast do F1 cars go during a race? A lot faster than a Hummer, I'm sure.