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Old 04-26-2016, 12:56 PM   #1 (permalink)
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Study: roof racks waste 100 million gallons of gasoline a year in the U.S.



A joint study by researchers from the Lawrence Berkeley National Laboratory (Berkeley Lab) and the National Renewable Energy Laboratory have revealed something shocking:

Roof racks are bad for fuel economy.

Kidding aside, they've quantified/estimated the scale of the problem to the national level based on the prevalence of roof racks in freeway traffic audits.

Findings:
  • in 2015, roof racks nationwide were responsible for 0.8 percent of light-duty vehicle fuel consumption, or 100 million gallons of gasoline
  • fuel consumption penalty can be up to 25% on passenger cars
  • people drive around with their roof racks empty eight times more than when loaded
  • roof rack prevalance is estimated to increase by about 200% in the next 25 years (yay, "crossover" craze!)
From: Roof Racks a Drag on Fuel Economy | Berkeley Lab

Full study: Fuel consumption impacts of auto roof racks

Related threads:

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Old 04-26-2016, 01:04 PM   #2 (permalink)
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...and I am seeing an add for roof racks! No thank you!
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Old 04-26-2016, 01:06 PM   #3 (permalink)
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It's a conspiracy I tell you!

...

Actually, I'm seeing an ad for an electric toothbrush. Is it still a conspiracy?
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Ecodriving test: Manual vs. automatic transmission MPG showdown



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Old 04-26-2016, 02:00 PM   #4 (permalink)
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Hold on, let me try Aragonis's method:

Despite opening fifty tabs about Star Wars toys, now I am getting Nissan and Officemax.

Kindly disregard my last transmission.
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Old 04-26-2016, 02:04 PM   #5 (permalink)
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I used to rant about useless- rather, never used- roof racks rather frequently. Good times.
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Old 04-26-2016, 02:07 PM   #6 (permalink)
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I get ads for Ram commercial trucks, they seem to be escalating the situation... I could get by with a roof rack but suddenly I feel the need for a 3500 Chassis Cab.

Actually I almost never have needed a roof rack. I do like the flat folding style on our minivan, maybe more companies could go that direction. Funny but I can't even find a picture or video on the Web of how it works! I bet a bunch of owners out there don't even know their van has a roof rack with fold away crossbars.
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Old 04-26-2016, 09:31 PM   #7 (permalink)
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I only use my roof racks when I actually need to carry something, usually my kayak. They are removed from the vehicle otherwise. Fortunately, it takes less than a couple minutes to install or remove them. In my fuel log, you can see the times when I use my roof racks. They definitely hurt fuel economy.
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Old 04-27-2016, 10:47 AM   #8 (permalink)
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90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
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fashion accessories

Same here - I have a set that hangs in my garage. I put them on a car maybe once or twice a year.

About 5 years ago I told my brother his factory roof racks were costing him 3-4% a year extra in fuel costs. They're still on. I've seen him use them twice.

Here's something new though: roof racks have become / are becoming a fashion accessory on the hip younguns' vehicles. I'm seeing more and more empty ones on lowered/stanced cars that are all stickerbombed, like this:

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Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



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www.MetroMPG.com - fuel efficiency info for Geo Metro owners
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Old 04-27-2016, 11:08 AM   #9 (permalink)
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I blame my wife's last car.

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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%

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Old 04-27-2016, 04:08 PM   #10 (permalink)
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Quote:
Originally Posted by MetroMPG View Post
Here's something new though: roof racks have become / are becoming a fashion accessory on the hip younguns' vehicles. I'm seeing more and more empty ones on lowered/stanced cars that are all stickerbombed, like this:
Classic VW crowd might own that one. :/

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