This works because of a system of gears, axles, differentials, and transfer case that allows the driver to select between different drive modes:
* 2WD (2-wheel drive): Power goes only to the rear wheels. This is best for fuel efficiency on paved roads.
* 4WD (4-wheel drive): Power is distributed to all four wheels. This provides significantly improved traction on slippery surfaces like snow, ice, mud, or loose gravel. This typically requires the driver to engage the 4WD manually via a shifter or dial. Different 4x4 systems have different engagement methods and capabilities.
* 4WD High: Used for most off-road conditions and moderate speeds.
* 4WD Low: Used for extreme off-road conditions, steep inclines, and low speeds. This gear reduction multiplies torque for better climbing ability and crawling over obstacles. Generally not used on paved roads.
In short, 4x4 works by mechanically transferring engine power to all four wheels, giving the truck significantly enhanced traction and off-road capabilities compared to a 2x4 vehicle.
