GMC asks drivers to think back to when they rode their first bike. No, not that dinky little thing they would pedal around the neighborhood as a kid, but their first real bike, the one they could use to power through winding mountain roads. "So, can you imagine the feeling you'll get from your first real truck?" the automaker asks. On cue, the GMC Sierra breezes through the serpentine curves and passes of the hilly countryside with what the company calls professional power.