| (1) Low Speed/Low Load |
Completely Advance |
* Valve Under-lap |
Completely Retard |
* Valve Under-lap |
| * Improvement of combustion stability |
* Improvement of combustion stability |
| (2) Part Load |
Retard |
* Increase of expansion work |
Retard |
* Reduction of pumping loss |
| * Reduction of pumping loss |
| * Reduction of HC |
| (3) Low Speed/High Load |
Retard |
* Increase of expansion work |
Advance |
* Prevention of intake back flow (Improvement of volumetric efficiency) |
| (4) High Speed/High Load |
Advance |
* Reduction of pumping loss |
Retard |
* Improvement of volumetric efficiency |