The remarkable Real Time 4-wheel drive system, available on all CR-V trim levels, increases drivetrain efficiency, decreases noise and vibration, and only operates in 4WD when necessary. Here is how it works: When there is insufficient traction at the front wheels, the Real Time 4WD system automatically uses dual hydraulic pumps to transfer power to the rear wheels. There is no need for driver intervention. The greater the degree of front-wheel slippage, the more torque is directed to the rear wheels. Best of all, Real Time 4WD requires little maintenance.