|
I believe the Nascar philosophy is the area under the car is so turbulent, it's better to keep all air out of there.
For some racing vehicles this includes the radiator exhaust as well.
Add the grain of salt to the above, they are also interested in down-force not just cd.
Trucks also have that big rear axle to drag through any air down there. Less air underneath = less to plow the differential through.
|