A four-wheel-drive system delivers power to all four wheels of a vehicle, enhancing traction compared to two-wheel-drive systems that power only two wheels. This difference becomes particularly significant in low-traction scenarios, such as those encountered on slick surfaces like wet roads. Imagine attempting to drive up a slight incline covered in wet leaves: a two-wheel-drive vehicle might struggle or even fail to ascend, whereas a four-wheel-drive vehicle could likely manage the task due to its enhanced grip.
Enhanced traction translates to improved vehicle control and stability, particularly in adverse weather conditions. This added stability contributes significantly to road safety, especially during rain, snow, or on icy roads. While anti-lock brakes and electronic stability control offer valuable support, a four-wheel-drive system provides a foundational mechanical advantage. Historically, four-wheel drive was primarily utilized in off-road vehicles; however, recognizing its safety benefits, manufacturers increasingly incorporated this technology into everyday passenger vehicles.