The trucks
we drove were stock versions, with no side rails or brush bars and with
9.3 inches of clearance in front and 8.4 inches in the rear, according
to GM’s specs sheet. At least three times each truck needed spotters
to help even experienced off-road drivers with tire placement so we could
get over particularly challenging obstacles, and even then there were
a couple of good whacks against the bottom of the 355s’ frames.
The new trucks ride on wheelbases that are three inches longer than the
previous model and the vehicles themselves also are longer, by as much
as 2.2 inches. Passenger compartments also are longer, and wider as well,
thanks primarily to better sculpting of interior door panels, which still
have room for both map and beverage pockets.
The Z-71
suspension puts torsion bars on the independent front setup with a live
axle and leaf springs in the back. We were impressed at how well planted
the rear end remained as it kept the tires in good contact with the rarely
smooth surface of the trails. It basically was if we were driving well-engineered
sport utility vehicles, which we mean as a compliment when applied to
pickup trucks, off or on pavement.
The push-button four-wheel-drive system with 4HI and 4LO settings also
did a nice job of putting the inline five’s grunt to the ground,
even getting us up some steep climbs on loose rock surfaces that led to
narrow but scenic routes along ridge lines and shelf roads.
GM worked hard to provide a second throttle map for proper response when
the Colorado and Canyon are in 4LO, though the vehicles are so capable
that we did nearly all of the trails in 4HI.
One key, one of the engineers explained, is that the new frame is so
stiff – 250 percent more resistant to torsional flex -- that suspension
could be properly tuned “to control the body and not just shake.”
Indeed, only extremely uneven surfaces caused much head tossing in the
trucks’ cabins.
The trucks
were impressive, and so was the setting, just 60 miles southeast of the
downtown business district of the country’s fifth-largest city.
