A Full-Time 4x4 system operates by default in four-wheel drive and can travel safely and securely on all surfaces. The system uses either a clutch or a center differential to allow the front and rear driveshafts to turn at varying speeds. Whether the road is covered in snow or is dry as dirt, this system can be utilized confidently.   All-Wheel Drive (AWD) is almost the same as full-time Four-Wheel Drive (4WD). It is also a system that powers all four wheels of a vehicle at all times. It can be used full-time on all surfaces, including pavement, like full-time 4WD. The only difference is that a ''4-low'' setting is not available on AWD vehicles. Due to the lack of ''low range'', AWD vehicles are much less capable in off-road settings than full-time 4WD vehicles, but work perfectly well on-road.   Part-Time 4WD operates by default as a two-wheel drive vehicle. Unlike the full-time system, part-time 4WD doesn’t use a center differential. The system instead locks the front and rear driveshafts, making it better for use exclusively during off-road travel or challenging road conditions. When on dry pavement or under normal driving conditions, the driver should switch to the vehicle’s two-wheel-drive mode. If drivers use Part-Time 4WD excessively, they may experience driveline noise or binding that can lead to overheating or early part failure.   On-Demand 4WD systems operate primarily in two-wheel drive during normal driving conditions. When a slippery surface such as snow or mud is encountered, 4WD is automatically engaged and power is transferred to the secondary axle.   Learn more about 4x4 systems