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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-26-2016, 05:18 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: Sep 2014
Location: Alaska
Posts: 98

n/a - '05 Ford Focus ZX3
Thanks: 5
Thanked 58 Times in 24 Posts
Roof rack fuel penalty nationwide (US)

(The abstract linked in the story is here: Fuel consumption impacts of auto roof racks)

Roof racks create drag, cost gas -- study

Ariel Wittenberg, E&E reporter
GreenWire, April 26, 2016

Bad news for anyone planning on strapping their bikes or kayaks to their car for a day trip this summer -- roof racks significantly limit fuel economy.

A new study from the Lawrence Berkeley National Laboratory, published in the journal Energy Policy, estimates that roof racks can cost drivers as much as 25 percent more in gas.

Berkeley researcher Alan Meier, working with Yuche Chen of the National Renewable Energy Laboratory, estimated the fuel consumption of the vehicle add-on.

Nationwide, they found that roof racks were responsible for 0.8 percent of light-duty vehicle fuel consumption -- 100 million gallons of gasoline -- in 2015.

"I've always been intrigued by energy consumption that was somehow overlooked or ignored because, for example, it wasn't in the test procedure," Meier said.

Placing a roof rack on a car creates an aerodynamic drag, which requires vehicles to expend more energy. Depending on the rack's configuration, it could create a fuel consumption penalty of zero to 25 percent on a passenger car.

"For comparison, the additional fuel consumption caused by roof racks is about six times larger than anticipated fuel savings from fuel cell vehicles and 40 percent of anticipated fuel savings from battery electric vehicles in 2040," the researchers wrote.

An abstract for the study explains that the researchers used a "bottom-up" approach to estimate national fuel consumption of roof racks. The duo were able to assess the fuel consumption impacts for several different vehicles using a computer model that incorporates real-world data and vehicle stock information. The researchers also created an energy inventory model to include rack usage rates, vehicle stock, vehicle-level roof rack fuel consumption penalties and vehicle miles traveled through 2040. The study considers the drag of roof racks both when they are loaded and when they are unloaded.

The pair wrote in their report that policymakers should consider crafting regulations to reduce the number of drivers traveling with empty roof racks on their cars. They also say a policy requiring energy labeling of roof racks could spur such a change.

Meier noted that making roof racks that are easier to remove could also prompt drivers to take them off their cars when they are not in use.

The study estimates that a government policy to reduce the use of unloaded roof racks, in combination with more energy-efficient rack designs, could save 1.2 billion gallons of gasoline over the next 26 years.

  Reply With Quote
The Following 4 Users Say Thank You to Focus-Ak For This Useful Post:
aerohead (04-27-2016), Fat Charlie (04-27-2016), MkVer (05-05-2016), spacemanspif (04-26-2016)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-26-2016, 05:43 PM   #2 (permalink)
Spaced out...
 
spacemanspif's Avatar
 
Join Date: Jul 2013
Location: Dirty Jersey
Posts: 695

The Focus - '07 Ford Focus ZXW SES
Team Ford
90 day: 36.13 mpg (US)
Thanks: 115
Thanked 192 Times in 139 Posts
Glad I took mine completely off shortly after I bought the wagon. These people didn't find anything we didn't already know but maybe more people will take their racks off and leave them in the garage instead of "storing" them in their roof for that once a year snowboard trip. Not to mention the people who just like they way they look and have never strapped anything to them.
__________________
-Mike

2007 Ford Focus Estate - 215k - SGII, upper grill block, partial lower grill block and roof rack delete
1987 Monte Carlo SS - 5.3/4L80E swap - 13.67@103.7
1995 Saturn SL2 - 256K miles - 44mpg - Retired - Sorely missed
Cost to Operate Spreadsheet for "The Focus"


  Reply With Quote
Old 04-26-2016, 09:39 PM   #3 (permalink)
EcoModding Lurker
 
Join Date: Jan 2015
Location: west TN
Posts: 74

Stream - '16 Volkswagen Jetta
90 day: 33.7 mpg (US)
Thanks: 8
Thanked 24 Times in 18 Posts
I had a chuckle when I noticed the etrailer.com roof rack ad on this page. I imagine the new trend of led light bars are just as bad as an unused rack...
__________________

  Reply With Quote
The Following 2 Users Say Thank You to bentring For This Useful Post:
Cd (04-30-2016), rumdog (04-30-2016)
Old 04-26-2016, 11:04 PM   #4 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 11,850

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,327
Thanked 2,817 Times in 1,797 Posts
A gummint policy

Just tell the auto mfg's marketing depts that nobody uses them so they AREN'T value-added.
__________________


  Reply With Quote
The Following User Says Thank You to Frank Lee For This Useful Post:
aerohead (04-27-2016)
Old 04-27-2016, 01:01 AM   #5 (permalink)
Ecomuggler
 
Xist's Avatar
 
Join Date: Jun 2012
Location: Mesa, AZ
Posts: 4,780

Chorizo - '00 Honda Civic HX, baby! :D
90 day: 42.03 mpg (US)

Mid-Life Crisis Fighter - '99 Honda Accord LX
90 day: 32.23 mpg (US)
Thanks: 2,709
Thanked 811 Times in 609 Posts
Study: roof racks waste 100 million gallons of gasoline a year in the U.S.
  Reply With Quote
The Following User Says Thank You to Xist For This Useful Post:
aerohead (04-27-2016)
Old 04-27-2016, 02:47 AM   #6 (permalink)
V8 guy
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 4,605

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)
Thanks: 98
Thanked 1,054 Times in 772 Posts
It is well established that a big ugly SUV roof rack can eat up to 2.5mpg.

For led light bars I put mine on my bumper.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
  Reply With Quote
Old 04-27-2016, 02:52 AM   #7 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 2,555

Acura TSX - '06 Acura TSX
90 day: 31.25 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Camry - '98 Toyota Camry
90 day: 27.09 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 71.46 mpg (US)
Thanks: 1,008
Thanked 772 Times in 512 Posts
This is one of the many reasons I mounted a hitch to carry bicycles instead of a roof rack. The other reason was to haul inappropriate loads of compost in a trailer.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
The Following User Says Thank You to redpoint5 For This Useful Post:
aerohead (04-27-2016)
Old 04-27-2016, 01:50 PM   #8 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 8,259
Thanks: 9,958
Thanked 4,304 Times in 2,381 Posts
Boeing announces roof racks for jetliners

Dateline: Dallas Aircraft Show.
Boeing Commercial Aircraft Division has announced the addition of roof racks for their full line of jetliners.
Running boards,bug deflectors,KC flying lights,and exposed exhaust stacks are also in the offing.
The modifications are a measure to meet customer demand.
Southwest Airlines will be the first customer according to Boeing's head of marketing.
A Southwest spokesman announced that airfares would not increase by more than 3-X.
The new aircraft should enter service by December 2016.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
The Following 2 Users Say Thank You to aerohead For This Useful Post:
BamZipPow (04-27-2016), Xist (04-27-2016)
Old 04-27-2016, 02:34 PM   #9 (permalink)
Tyrant-at-large
 
Vman455's Avatar
 
Join Date: Feb 2012
Location: Champaign, IL
Posts: 771

Little Red - retired - '05 Honda Civic EX
90 day: 49.03 mpg (US)

Pope Pious the Prius - '13 Toyota Prius Two
Team Toyota
90 day: 49.72 mpg (US)
Thanks: 72
Thanked 611 Times in 307 Posts
Without roof racks, how will people advertise their "active" lifestyles to everyone else in the Walmart parking lot?
__________________

  Reply With Quote
The Following 5 Users Say Thank You to Vman455 For This Useful Post:
101Volts (06-06-2017), aerohead (04-27-2016), Cd (04-30-2016), Frank Lee (04-27-2016), Mustang Dave (04-30-2016)
Old 04-27-2016, 02:52 PM   #10 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 8,259
Thanks: 9,958
Thanked 4,304 Times in 2,381 Posts
31-Flavors

Yes,an 'active' lifestyle is but one of Wall Street's pre-approved, Baskin-Robbins 31-Flavors of lifestyles permitted for U.S. consumers.
Obey your television! And you'll be fine to mate and spread your spawn across the face of the Earth,worshiping at the nearest franchised retail outlet.

__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com