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.

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.

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...

A gummint policy :rolleyes:

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

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.

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.

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.

Without roof racks, how will people advertise their "active" lifestyles to everyone else in the Walmart parking lot?

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.

Challenge accepted? (Example: a steamer trunk on the aerocivic.)

Oh, come on. They'll have to show their work on this one.

2 data points
 

CAR and DRIVER measured:
*1981 Ford Escort at 60-mph,with 12-cubic foot cargo carrier = 6-mpg loss.
*1982 VW Scirocco,with empty roof rack @ 55-mph = 13% mpg loss.

6 is 13% of 46, but there's the 5mph difference.

Journalists!

difference
 

Actually,we need the baseline for each vehicle so as to know the % difference for the Escort,and the mpg difference for the Scirocco.
And we'd have to make presumptions about rolling resistance and BSFC if we attempt to predict at a different velocity.

Can we merge threads? :)

I guess I have to do everything:

http://ecomodder.com/forum/showthrea...tml#post513135

It's an H2 so you might as well put a huge home made roof rack on it.
Custom H2 roof rack build

What in the world is he planning on carrying up there?!

I admire the craftsmanship though. If you're gonna build it, build it right!

I see more people using roof racks as an ornament than actually hauling something with it.

x2 - Yeah he did a nice job, but I suppose when your mileage is as bad as an H2 you really don't care about fuel economy.....shrug.

I read some of the post and it looks like that H2 is their second or weekend vehicle. Not your typical 10,000 to 15,000 mile per year daily driver.

In post 7 he sez the Prius' will tremble and wet themselves.

There's Prius' out on the trails? :confused:

Ooooooh... right! It's for commuting!

I see his main hobby is reproducing. There is absolutely nothing I like about this ******* except it looks like he does nice welds.

Been working the Philadelphia/NYC/ New England area the past month. Pretty funny to see all the roof racks. Mainly empty. But the all important kayaks and bicycles on weekends. Waiting for the same self obsessed to also preach from their Subarus that I'm on the wrong side of history. Cracks me up, the bumper stickers and the rest.

Some folks claim they use empty roof racks as a sacrifice anode, when it's made out of a lower-grade sheetmetal.

rack
 

this was online.pretty sadistic.
http://i1271.photobucket.com/albums/...titled3_34.jpg

Just pulled xbars off of ol Eddie. Hopefully put me over 23 mpg. Just think if a half mile per gallon improvement were done at least begining of the vehicles lifetime. 260k miles. Granted I get 22 my wife was getting 18. Just say lifetime 18. So 14,444 gallons of gas. We will call it 1.80$ per gallon seeing as it's an 02. 26,000$ of gas vs .5 mpg better 25,297. That's over 700$ now implement our driving plus aero over 260000. Would have saved 5,700$. That's more than all of my cars cost except the Cruze. Thats half.

Added partial upper grille block as well

The very first thing I did on my 87 740 Volvo Turbo wagon when I was modding it for highway fuel mileage was rip off the factory roof rack.

That was a no brainer. :)

I know it's hard to track numbers for removing something as fickle as a xbar on a roof rack but it seems that with the grill block allowed for almost 5mph faster 60 vs 55 to obtain 22.5 mpg. So 4-5 mph achieved the same mpg. Mind you this is with oil temp never breaking 170°. When all the way to operating temp it will run closer to 24 at least pre mods. Haven't had an opportunity to get it out lately. It's summer can't help but enjoy the Cruze getting 60 mpg. Will update when I get it out for more than 20 miles.

https://www.facebook.com/groups/arct...6926993854679/

Here is my take on roof racks.

The link goes to something about extinction rebellion. I'm never clicking a FB (whatever that was) link again. FB is just awful, unlike the contributions here.

Extinction rebellion looks like the environmental movement for white supremacists.

They want the UK government to pretend that climate change is a huge emergency.
Good distraction, once you realize you can not solve or are unwilling to solve the actual problems of society, just make up a new fake non existent problem, waste time and resources on solving the made up problem to feel some sense of accomplishment.

Well oil pan would if we all become richer fighting climate change? Or do you just hate the idea of anything that would cause fossil fuels to go away?

In what way is that an argument for Supremacism? I'd avoid that label as it is used by the regressive Left to disparage everyone from the center rightward. Got milk?

non existant
 

Yeah,those lucky folks who were killed or injured in the record tornadoes over the weekend are loving the fake emergency.:thumbup:

All ?

A few are becoming richer because of it.
Most are losing.

Technically, I believe we would be richer. That's how we get to today's conditions, ignore the environment for the sake of profit.

Fyi. I'm not a tree hugger.

I'm becoming richer bidding fairwell to fossil fuels.
The nissan leaf with home CHAdeMO and wiring in massive over kill of 240v charging capacity to the garage is saving me $150 to $200 per month in gas.
My wood stove and coal furnace saved me $50 to $100 in electricity just November.
The solar panels I'm putting up will reduce my power bill around $40 per month.
My well will eliminate my $50 water bill, not really fossil fuel related but involves me getting richer.
Next summer I figure out how to wire and plumb in my hot water heater heat pump, should at least cut my water heater power requirements at least in half.

Most everyone else can expect to get poorer.
Gas prices go up, something like 80% to 90% of people say they can't or won't or can't go electric most people are buying gas guzzlers. Oh well, their loss.
Electricity will get more expensive and will get much more expensive if the believers, nimby and other useful idiots have their way. The vast majority of people can't put up solar panels for some reason or another.
Most people can't or won't use a wood stove, electrical natural gas and liquid heating fuels will just get more and more expensive over time.
Water is getting harder to get, just ask California. I got a 16 inch bore well that is certified to pump 100gpm.

Unfortunately you speak from experience, right?