Tux To Trail, Denali Ultimate And AT4X Have It Covered

The Sierra AT4X goes beyond the AT4 off-road package by adding an X. Several other additional important details add to the AT4 as well: most notably Multimatic DSSV spool-valve dampers, which are position and speed sensitive, and help control the big truck no matter the road or trail.

These dampers have been fitted to the Chevy Colorado ZR2 in the past, among other performance vehicles, and the feel is nothing short of magical. Our initial drive route through the mountains east of San Diego led us on roads much better suited for lithe sports cars than a half-ton truck, with narrow lanes and switchbacks. The Sierra AT4X hucked around corners at speeds well out of character for such a big vehicle, especially considering the standard Goodyear Wrangler Duratrac 32″ mud terrain tires.

Chris Tonn/SlashGear

Those tires and dampers acquitted themselves nicely once we met our destination in the desert, where after airing the Goodyears down to 15psi we blasted over washboard surfaces and crawled through rocky terrain.

When the trail looked less beaten and more natural, the terrain mode (available when the transfer case is switched into 4WD low) was quite welcome. This allowed for driving with one pedal, automatically activating the brakes as you lift off the throttle. Much finer control over slow, technical terrain was afforded.