John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.
Researchers say roof racks are “responsible for almost 1 percent of national fuel consumption.”
Having a car rack for bikes or kayaks is a good way to show the world that you’re an outdoorsy, planet-loving person. But those contraptions might be taking their own toll on the environment by devastating your vehicle’s fuel consumption.
Last year alone, roof racks ate up some 100 million gallons of gasoline throughout the U.S. due to their aerodynamic drag, according to a new study in Energy Policy. That represents about 0.8 percent of national fuel consumption by light-duty vehicles, say co-authors Yuche Chen of the National Renewable Energy Laboratory and Alan Meier of Berkeley Lab.
In fact, they say the simple act of putting a rack on your ride can (depending on how it’s attached) cost you up to 25 percent more in fuel consumption. That’s not just a problem for your wallet but possibly for the climate, too, as the use of racks is estimated to jump 200 percent by 2040. Here’s more from a Berkeley press release:
“A national perspective is still needed to justify policy actions,” the authors write. “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.”...
[M]anufacturers have found that it is possible to make roof racks with greatly improved aerodynamics. A policy to require energy labeling of roof racks could spur greater changes, the researchers note.
Even greater energy savings would come from removing roof racks when not in use. Meier notes that they could be designed so as to be easier to remove. The researchers estimated that a government policy to minimize unloaded roof racks (admittedly extreme) in combination with more energy-efficient designs would result in cumulative savings of the equivalent of 1.2 billion gallons of gasoline over the next 26 years.