Two Sierras, two very different missions! We break down the AT4 and AT4X in terms of suspension, off-road capability, pricing, and more. The AT4 runs Rancho Monotube shocks and a locking rear diff.

Many dedicated off-roader fans prefer to build their rigs from scratch, opting for more basic stock trucks, then upgrading them with varying degrees of intense aftermarket parts. This can be a great ...

The GMC Sierra AT4 is already a serious off-road truck. Two-inch factory lift, skid plates, four-wheel drive, hill descent control. It's not pretending. So when GMC introduced the AT4X, the natural ...