[Scarrzz]

Originally Posted by Number 3

You are correct, aerodynamics do matter quite a bit. Once you clear 55 to 60 mph it becomes a bigger deal.

At highway cruising speed 3 things matter moving a vehicle down the road.

Powertrain (engine and drivetrain)

Rolling resistance (weigh of the vehicle pressing the tires on the road)

Aerodynamics (air flow over and around the vehicle)

At cruising speed, aero is 50% of the equation, as much as the other two.

And aero consists of two elements, Coefficient of Drag, Cd and Cross Sectional Area, A. That is CdA. So being slippery and small matter.

Now to take that a step further and look at a car designed to rule on the road course, you actually want to increase the effective rolling resistance to create "down force". This is done using aerodynamics as well. So the Z/28 and the Z07 package on the Corvette are intended to this. So to be great on the track you are doing things counter to what you want for a car to move easily down the road by making aero worse in order to selectively make rolling resistance worse.

And the HP required to overcome aerodynamics/down force goes up exponentially with speed.

Aerodynamics was my second favorite course back in college, right behind Babeology.