2001 GMC 2500HD Crew cab shortbox 4x4 LB7:

1820 miles - round trip from western Montana - Las Vegas SEMA show. Each 910 mile leg took 13 hours and 20 minutes, for a 68+ mph average speed (which included fuel & convenience stops). Where possible, the truck's speedo hovered around 85 (65 through Salt Lake and in the mountains north of Salmon, ID on US-93). Calculated fuel economy for each tank ranged from 18.5-mpg to 20.2-mpg. Best tank was the last leg from Idaho Falls, ID to Missoula, MT. Just me and about 100-lbs of gear in the truck. The 265 Michelins were aired to 70-psi front and 60-psi rear. Mobil Delvac 1 synthetic in the engine. Power Service fuel treatment used at the recommended mix ratio. One tank was B5 (Sinclair station in LV). Otherwise, all tanks but one were ULSD. And.... the VanAaken module was turned off for the entire trip.

Jim