All-wheel drive (AWD) is a system in which a vehicles engine sends power to all four wheels, whether full-time or on-demand. AWD is optimized for on-road use and is engineered to enable each tire to rotate at its own speed in turns, making it a better system than four-wheel drive for the average driver seeking bad-weather security. AWD vehicles are particularly loved by people who live in areas where the weather tends to be snowy and rainy, as the system offers additional traction on slippery roads, making drivers more confident in handling.

There are two types of AWD systems: full-time AWD and part-time AWD. Full-time AWD powers all four wheels at the same time, while part-time AWD has the capability of delivering power to all of the tires but only does so when it is required. Most of the time, it runs on two-wheel drive mode. Both full-time and part-time AWD systems usually operate without direction from the driver, and all four wheels, instead of two, receive torque through a set of axles and spin at different speeds simultaneously.

AWD can be used on pavement with no ill effect because it is designed to enable each tire to rotate at its own speed in turns, making it a better system than four-wheel drive for the average driver seeking bad-weather security. AWD is available on a wide selection of cars, crossovers, and SUVs, and it is even increasingly offered in pickup trucks, the longtime domain of four-wheel drive.