View Single Post
Old 01-21-2013, 11:14 PM   #3 (permalink)
NeilBlanchard
Master EcoModder
 
NeilBlanchard's Avatar
 
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,908

Mica Blue - '05 Scion xA RS 2.0
Team Toyota
90 day: 42.48 mpg (US)

Forest - '15 Nissan Leaf S
Team Nissan
90 day: 156.46 mpg (US)

Number 7 - '15 VW e-Golf SEL
TEAM VW AUDI Group
90 day: 155.81 mpg (US)
Thanks: 3,475
Thanked 2,952 Times in 1,845 Posts
The thing about outboard wheels is that while the frontal area is smaller (all else being equal) but you have exposed the suspension bits to open air flow, and you have to be concerned with interference of the flow around the larger main part of the car and the outboard wheels. The plan shape of the wheel fairings are not likely to be symmetrical - the channel between the main part of the car and the outboard wheels will require something different than the air flow past the outside of the wheel fairings.

Those suspension bits are designed for the structural requirements, and they will not likely be all that great for low turbulence air flow.

If you cover the suspension bits, then you have to choose which thing the wheel fairings are attached to - the wheel of the main chassis. This then adds to the complexity, either by adding unsprung weight, or structurally attaching the fairing to the main chassis while allowing the wheel and suspension to move inside it.

The front wheels also have the added complication that they swing through a fairly wide arc when steering sharply, and there has to be enough clearance for this; as the suspension travels up and down in the steering lock position. With a wider wheel, the fairing extends farther back, and this requires proportionally more clearance.

Phil, I seem to remember that you posted a comparison done by Mercedes many years ago, between a single-mass car and an car with outboard wheels. What were the details on the differences?
__________________
Sincerely, Neil

http://neilblanchard.blogspot.com/
  Reply With Quote