Just back from 2k plus miles thru hills of West Virginia - NOT a flat state by any means! Towing 3200# Suby up, down, and around - Sprinter did very well. Have had it and toad out thru mountains of CO, too. Plenty of power - most torque around 2800 rpm, IIRC. Do have Scangauge installed, so monitor LOD (engine load, if you will) - as LOD approaches 90%, I simply slow down and downshift to keep LOD to 80-85%. Not afraid to climb hills at 40-45 mph - similar to OTR trucks on climbing lanes - keeping RPMs around 25-2800 and LOD in low 80s. Using this "formula", still getting 15 mpg on average, high was 15.8 this trip, and that's fully loaded and pulling toad. So can't complain about power available. ST