GMC motorhome goes 120.8 mph at Speed Week

September 4, 2013 by Kelly Cauthorn

(Sept. 4, 2013) -- During Speed Week 2013 in Bonneville, Utah, AutoWeek took a glance at the Palmer Designs GMC Motorhome. The Palmer guys are shooting to break the current speed record for motorhomes, which is 137.9 mph.