All-wheel drive (AWD) is a type of drivetrain that can send power to all four wheels to help improve traction.
AWD systems automatically distribute power between the front and rear wheels as driving conditions change. Some systems primarily deliver power to one axle during normal driving and send power to the other when additional traction is needed. Other systems continuously send power to both axles and adjust the amount going to each. In most AWD vehicles, this happens automatically without driver input.
AWD is common in crossovers, SUVs, and some cars and trucks. It is designed primarily to improve traction during everyday on-road driving, while 4-wheel drive (4WD) is generally better suited to more demanding off-road conditions.
MORE: AWD vs. 4WD: Which Is Better?
AWD can provide additional traction on slippery surfaces, including rain, snow, gravel, and loose pavement. It can help a vehicle accelerate from a stop or maintain traction when the driven wheels might otherwise slip.
There are trade-offs. AWD does not necessarily help a vehicle stop more quickly on slippery roads because braking depends largely on the tires and available grip. Proper tires remain important regardless of drivetrain. AWD systems can also add weight, complexity, and cost compared with 2-wheel-drive (2WD) vehicles and may reduce fuel economy.
MORE: What is Front-Wheel Drive?, What is Rear-Wheel Drive?
Some hybrids and electric vehicles use an electric AWD system rather than a mechanical driveshaft connecting the front and rear axles. A separate electric motor can power the second axle when additional traction or performance is needed.
Editor’s Note: We have updated this article since its initial publication.
