View Single Post
Old 12-27-2009, 12:11 PM   #5 (permalink)
Master EcoModder
JasonG's Avatar
Join Date: May 2009
Location: Charlotte NC / York SC
Posts: 726

05 DMax - '05 Chevrolet 2500HD
90 day: 18.48 mpg (US)
Thanks: 107
Thanked 54 Times in 50 Posts
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.

I can't understand why my MPG's are so low..........
21,000lb, 41' Toy Haulers are rough on FE!
  Reply With Quote