This two-image gallery documents the 2014 GMC Sierra Regular Cab during aerodynamic wind tunnel testing at GM's testing facility, with smoke streams visualizing airflow around the white pickup's front fascia, hood, and lower air dam. The redesigned Sierra Regular Cab benefited from extensive aero work as part of its full-size truck redesign for the 2014 model year. Read the 2014 GMC Sierra Regular Cab debut coverage.