Photos 2014 GMC Sierra Regular Cab Autoblog Staff Aug 8, 2013 A 2014 GMC Sierra pickup undergoes testing in the GM Aerodynamics testing. Time spent in the lab led to advancements in body design and sealing. A 2014 GMC Sierra pickup undergoes testing in the GM Aerodynamics testing. Time spent in the lab led to advancements in body design and sealing. The 2014 GMC Sierra's new front air dam directs air out and around the truck's tires, benefitting the truck's aerodynamic efficiency. open fullscreen close fullscreen facebook twitter email reddit linkedin pinterest List
