GMC has just launched its AT4 sub-brand with this, the new Sierra AT4. Fitted with a two-inch suspension lift and a locking rear differential, it’s a meaty, off-road inclined pickup that’s as much at home shifting a few motorbikes into the wilderness as it is doing the weekly shop.
It’s the first pickup to offer a carbonfibre load bay surface, albeit as an option, after we reported the switch a few months ago. The bed, sides and bulkhead will all be carbonfibre, while the inside surface of the tailgate sticks to a glass fibre composite. Whether steel or carbon, the front bulkhead has more tie-down hooks and three indents for motorbike wheels, making it easier to secure and stabilise bikes during loading.
The AT4’s design is a dark affair. Black chrome and with touches of red add a little purpose to the style, while textured aluminium on the steering wheel and Kalahari colour accents on the seats mix things up a little. On the outside, 18-inch wheels with mud tyres are standard-fit, with 20s and less aggressive all-terrain rubber optional.
As far as the greasy bits go, the two-inch lift sits over several bash plates and a two-speed transfer case with a low-range option for crawling. There’s hill descent control, that locking rear diff and a selection of driving modes for different terrain. Rancho monotube shocks, tuned for off-road driving, control the bounce.
A series of cameras gives a 360-degree surround view, while a ProGrade Trailering System with Trailering App makes it easier and safer to tow stuff.
Up front (and up high) is a 5.3-litre V8 used in other GMC trucks, pushing out 355bhp and 383lb ft. The two upgrades are, for efficiency, a 3.0-litre Duramax diesel or a 6.2-litre petrol V8 with 420bhp and 460lb ft. Both petrols have clever cylinder deactivation tech that can allow the AT4 to burble along on as little as one cylinder. A 10-speed automatic is standard with both upgraded motors.
Optional extras on the AT4 span a rear-facing camera display in the rear-view mirror for safer reversing, blind spot warnings, autonomous emergency low-speed braking and lane-change warnings.
The Sierra AT4 goes on sale this autumn, with prices to be confirmed later in the year. Beefed-up AT4 versions of all GMC’s models will follow.