How Consumer Reports tests cars:

Off road capability

We check off-road capabilities for vehicles made for or advertised for off-road use. SUVs or pickups with a traditional four-wheel-drive system that includes low-range gearing or some equivalent are put to the test on varying terrain. We evaluate the vehicle's 4WD system and the driver's ability to modulate the throttle—something vital for climbing over tricky obstacles. We also judge ground clearance, axle articulation, and, of course, traction.