Until electric vehicles and hybrids become de rigueur, fossil fuels will continue to power the vast majority of America’s automobiles for the foreseeable future.
And as it happens, America’s lumbering big rigs use up a lot of this non-renewable resource. A Fast Company article puts it bluntly: “Trucks are miserable when it comes to gas mileage. America’s 2.2 million freight trucks get about six miles per gallon on average, usually with cargo.” All told, that’s 36 billion gallons of diesel fuel burned annually by freighters.
But a study from the Lawrence Livermore National Laboratory found that adding trailer skirts, tail fins and other drag-reducing devices to America’s fleet of semi trucks can mean big savings in fuel consumption and dollars, as well as significantly cut CO2 emissions, Ensia reports.
The skirt (which is attached to the lower sides of a trailer) and the tail (which is affixed to the back) works by reducing air resistance over and around the vehicle as it moves along the road. According to a news release, researchers found that these panels — which are only utilized by 3 to 4 percent of the nation’s semi trucks — can reduce aerodynamic drag by as much as 25 percent, which represents about a 13 percent decrease in fuel consumption.
“Even a minor improvement in a truck’s fuel economy has a significant impact on its yearly fuel consumption,” says lead researcher Kambiz Salari in a statement. “For example, 19 percent improvement in fuel economy, which we can achieve, translates to 6.5 billion gallons of diesel fuel saved per year and 66 million fewer tons of carbon dioxide emission into the atmosphere. For diesel fuel costing $3.96 per gallon, the savings is about $26 billion.”
It might take some time and effort to retrofit millions vehicles with these fashionable-sounding accessories, but the hardware would help the nation’s heavy-duty trucks meet President Obama’s strict new fuel standards (he’s ordered a 10 to 20 percent increase in fuel economy by 2018, depending on class of truck). In a speech, the president noted that these vehicles only make up 4 percent of traffic on America’s roads, but account for 20 percent of the carbon pollution from the transportation sector.
Encouragingly, California’s trucks are already suiting up. The state’s Air Resources Board mandated the installation of trailer skirts in 2013, and it’s already paying off for some. A trucking company owner tells the Times-Tribune that the skirts, which cost about $1,500 to $2,000 each, pay for themselves in three or four years. Another trucking owner adds that they also save two-tenths to three-tenths of a mile per gallon on a trip, which amounts $2,000 to $3,000 in savings, per year, per truck.