GMC worked hard to optimize the aerodynamic efficiency of its new Sierra, now revealed in standard cab format.
It goes without saying that a pickup truck isn't exactly the most aerodynamic vehicle on the road. Pickups have large frontal areas, with squared-off cabs that drop off into cargo boxes – about as aerodynamically efficient as the side of a barn. Still, in an effort to improve performance, fuel efficiency and interior sound levels, truck manufacturers like GMC are always trying to make their pickups more aerodynamic. The latest GMC Sierra, for example - pictured here for the first time in single-cab setup - was tested in General Motors' state-of-the-art wind tunnel to optimize efficiency.
GM's wind tunnel is 750 feet long and is powered by a 43-foot-tall fan that uses 4,500 horsepower to simulate speeds of up to 138 mph. It's things like that which, according to GM, makes the Sierra ((and its twin, the Chevy Silverado) the most fuel-efficient V8 pickup on the market. GM also points out that, contrary to popular perception, the wind is actually best channeled with the tailgate in the upwards/closed position, not removed or left flat with the cargo bed. Tonneau covers (particularly soft ones) help channel airflow, but a rear cargo net in place of the tailgate actually harm aerodynamic efficiency.