This mechanism improves fuel efficiency and reduces exhaust emissions at all levels of engine speed, vehicle speed, and engine load.

The VTEC system changes the cam profile to correspond to engine speed. It maximizes torque at low engine speed and output at high engine speed.

The valve pause cam (low lift cam) is used at low engine speeds, and the high lift cam is used at high engine speeds.

The rocker arm oil control solenoid switches the intake valve side of the VTEC system on and off; the solenoid is controlled by the ECM.