View Single Post
Old 03-04-2008, 03:35 PM   #7 (permalink)
Master EcoModder
tasdrouille's Avatar
Join Date: Jan 2008
Location: Mirabel, QC
Posts: 1,672

The Guzzler - '08 Hyundai Elantra GL
90 day: 33.12 mpg (US)

Got Soul? - '11 Kia Soul 2U
Thanks: 35
Thanked 86 Times in 57 Posts
Originally Posted by apgrok1 View Post
So a roof tail would be bad
On a notchback yes as it would potentially prevent the flow to reattach at the trunk. On a squareback they can be desirable if they taper the roofline down at a 12 degrees or so angle.

Originally Posted by apgrok1 View Post
VG's are good
On a notchback yes, they can help reattach the flow on a shorter distance. On a squareback, which is a lot like a trailer, there are some sources saying that they can be used to create what looks like a boat tail made out of vortices (SAE paper 2003-01-3377 as an example).

VG's have a minimal impact on FE however you look at it though.

Originally Posted by apgrok1 View Post
the longer the tail fairing, the better, right?
Yes. Past a certain lenght the drag reduction is marginal though.
__________________ - Quand chaque goutte compte...
  Reply With Quote