All Wheel Drive or 4 Wheel Drive ? Find out the difference between AWD & 4WD

Generally, the terms 4WD (Four-Wheel Drive) and AWD (All Wheel Drive) both describe vehicles in which engine power is transmitted to all four wheels, unlike normal vehicles in which only two wheels receive torque from the engine.

Although 4WD and AWD sounds similar, there are some functional and design differences between both systems. The term 4WD describes a drive system in which the engine's power can be switched between two speed ranges and transmitted to all four wheels. AWD drive system lacks the two speed transfer feature. By having this  feature 4WD is considered superior to AWD.

Another key difference found between today's AWD and 4WD vehicles is, how engine power is shared between front and rear wheels. Under normal driving, AWD vehicles deliver 90 percent of its engine power to the front wheels. Additional engine power is diverted to rear wheels via viscous coupling, only when the front wheels start to slip. On the other hand, usually a 4WD transmits almost all of its engine power to the rear wheels. The second speed option available in 4WD allows to split the engine power equally between front and rear wheels.