Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 11-19-2014, 02:36 PM   #1 (permalink)
EcoModding Apprentice
 
Join Date: May 2014
Location: The Netherlands
Posts: 114

Volvo 360 - '85 Volvo 360

Peugeot - '01 Peugeot 306
Thanks: 47
Thanked 96 Times in 34 Posts
Roofrails, good or bad?

I have recently removed the roofrails of my car, because they never get used and increase drag. However, on new wagons/estates I'm am noticing a trend.

All of these new cars have roofrails which are closed on the sides.

2014 Ford Mondeo Wagon


2014 Honda Civic Tourer


2014 Peugeot 308 SW


Is this a styling thing of the past, because most people want roofrails on a wagon, or are they actually channeling air across the roof to the rear spoiler in a better way?

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 11-19-2014, 02:49 PM   #2 (permalink)
Rat Racer
 
Fat Charlie's Avatar
 
Join Date: May 2011
Location: Route 16
Posts: 4,150

Al the Third, year four - '13 Honda Fit Base
Team Honda
90 day: 42.9 mpg (US)
Thanks: 1,784
Thanked 1,922 Times in 1,246 Posts
It's not so much that people think wagons need side rails, as such, it's that wagons are much more likely than other cars to haul cargo. The old style clamp on roofracks are bad for door seals, so having side rails on from the factory is the best way to go. As long as you're stuck having something visible, let the stylists go at it.
__________________

Quote:
Originally Posted by sheepdog44 View Post
Transmission type Efficiency
Manual neutral engine off.100% @MPG <----- Fun Fact.
Manual 1:1 gear ratio .......98%
CVT belt ............................88%
Automatic .........................86%

  Reply With Quote
The Following User Says Thank You to Fat Charlie For This Useful Post:
Sven7 (11-19-2014)
Old 11-19-2014, 02:52 PM   #3 (permalink)
Master EcoModder
 
Sven7's Avatar
 
Join Date: Aug 2011
Location: Warren, MI
Posts: 2,456

Boo Radley - '65 Ford F100
90 day: 13.28 mpg (US)
Thanks: 782
Thanked 667 Times in 409 Posts
Many times they do double duty protecting the roof from luggage scratches and covering the roof seam. They're not there to improve aero.
__________________
He gave me a dollar. A blood-soaked dollar.
I cannot get the spot out but it's okay; It still works in the store
  Reply With Quote
Old 11-19-2014, 02:56 PM   #4 (permalink)
Master EcoModder
 
aardvarcus's Avatar
 
Join Date: Apr 2012
Location: Evensville, TN
Posts: 676

Deep Blue - '94 GMC Suburban K2500 SLE
90 day: 23.75 mpg (US)

Griffin (T4R) - '99 Toyota 4Runner SR5
90 day: 25.43 mpg (US)
Thanks: 237
Thanked 580 Times in 322 Posts
I think they also might be serving as drip rails/rain gutters to keep the water from the roof from soaking you when you open the door. I was noticing almost exactly the same sort of step up on the roof of my Tacoma, where the top of the door forms a higher step.

Edit: Not the best picture, but you can see the raised portion on the sides by the doors which is taller than the roof.
Attached Thumbnails
Click image for larger version

Name:	Roof.jpg
Views:	142
Size:	22.6 KB
ID:	16449  

Last edited by aardvarcus; 11-19-2014 at 03:01 PM..
  Reply With Quote
Old 11-19-2014, 06:58 PM   #5 (permalink)
Spaced out...
 
spacemanspif's Avatar
 
Join Date: Jul 2013
Location: Dirty Jersey
Posts: 748

The New Focus - '07 Ford Focus ZX5
90 day: 32.44 mpg (US)
Thanks: 142
Thanked 205 Times in 149 Posts
Are the rails on those above pictures prepped for cross bars? They look much lower than most side rails and almost look like if they use cross bars that the bars would need a "table" type shape where the cross bars are basically propped up above the side rails in order to keep luggage off the roof. If this is the case, then it looks like the car companies have given the roof rack some much needed attention and come up with a darn good compromise. The rack on my 07 is crazy tall and MetroMPG keeps telling me to delete mine because of the added drag in cross winds specifically. Sure wish I had a nice low profile roof rack for the couple times I'll need one in my life lol
__________________
-Mike

2007 Ford Focus ZX5 - 91k - SGII, pending upper and lower grill bocks - auto trans
1987 Monte Carlo SS - 5.3/4L80E swap - 13.67 @ 106
2007 Ford Focus Estate - 230k - 33mpg - Retired 4/2018
1995 Saturn SL2 - 256K miles - 44mpg - Retired 9/2014

Cost to Operate Spreadsheet for "The New Focus"

  Reply With Quote
Old 11-20-2014, 03:49 AM   #6 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,562
Thanks: 7,738
Thanked 8,554 Times in 7,041 Posts
Those are longitudinal fences. They are there to kill lift if you get sideways at high speed.

  Reply With Quote
The Following User Says Thank You to freebeard For This Useful Post:
aardvarcus (11-20-2014)
Old 03-14-2017, 05:40 PM   #7 (permalink)
aero guerrilla
 
Piwoslaw's Avatar
 
Join Date: Oct 2008
Location: Warsaw, Poland
Posts: 3,691

Svietlana II - '13 Peugeot 308SW e-HDI 6sp
90 day: 58.1 mpg (US)
Thanks: 1,269
Thanked 721 Times in 458 Posts
Quote:
Originally Posted by freebeard View Post
Those are longitudinal fences. They are there to kill lift if you get sideways at high speed.
At high speed? Maybe... Yet another reason why ecomodders don't need them.
__________________
e·co·mod·ding: the art of turning vehicles into what they should be

What matters is where you're going, not how fast.

"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell


[Old] Piwoslaw's Peugeot 307sw modding thread
  Reply With Quote
Old 03-14-2017, 09:45 PM   #8 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 27,562
Thanks: 7,738
Thanked 8,554 Times in 7,041 Posts
I was making a joke. You don't see the similarity?
  Reply With Quote
Old 03-15-2017, 03:10 AM   #9 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 12,548
Thanks: 0
Thanked 1,622 Times in 1,447 Posts
These newer roof rails seem to have a reasonably aerodynamic profile, quite like deflectors and may have some effect to reduce parasitic drag, in a way similar to the winglets fitted to aircraft.
  Reply With Quote
Old 03-15-2017, 08:59 AM   #10 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 4,158
Thanks: 120
Thanked 2,790 Times in 1,959 Posts
Quote:
Originally Posted by spacemanspif View Post
Are the rails on those above pictures prepped for cross bars?
Yea, it's what they do to get the fleet averages up.

Do what you have to do.

__________________
George
Architect, Artist and Designer of Objects

1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft

Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com