Engineers at the University of Vermont have proven that strapping Christmas trees to the top of sport utility vehicles burns extra gas. UVM associate professor of engineering Darren Hitt and a PhD student discovered that SUVs topped with trees have 26 percent more aerodynamic drag than tree-less SUVs.
They say that results SUVs using an extra 53,000 gallons of gas a year – about $100,000 in extra fuel costs nationwide. They based their research on a 2004 Ford Explorer, a seven-and-a-half-foot tree wrapped in plastic netting, and a ten-mile round trip to a tree lot.