View Single Post
Old 07-15-2009, 05:26 PM   #6 (permalink)
aerohead
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,024
Thanks: 24,117
Thanked 7,268 Times in 4,686 Posts
frontal area

I tossed your numbers around on Al's calculator.30-inches of added frontal area to a car with say,20-square feet of frontal area would raise the drag by 1-%.The mpg penalty at 55-mph could not be over 0.5%.Since a jump between 35 and 37 is on the order of 5% mpg,the wheel skirts should not be able to alter the mpg to this magnitude.I think there is more going on than just the skirts.Just my guess.
  Reply With Quote
The Following User Says Thank You to aerohead For This Useful Post:
landsailor (06-11-2011)