Kia Rio: CVVT (Continuously Variable Valve Timing) System: Operation Principle
The CVVT has the mechanism rotating the rotor vane with hydraulic force
generated by the engine oil supplied to the advance or retard chamber in accordance
with the CVVT oil control valve control.
Continuous Variable Valve Timing (CVVT) system advances or retards the
valve timing of the intake and exhaust valve in accordance with the ECM control
signal which is calculated by the engine ...
(1) Low Speed / Low Load
(2) Part Load
(3) Low Speed / High Load
(4) High Speed / High Load
...