Normal ignition timing: Optimization

A matrix (map, kennfeldt) in the control module memory contains the ignition timing for each respective load and engine speed.

Ignition timing is optimized to find the best compromise between torque in the actual operating point, which is also the best efficiency and thereby best fuel economy, and NOx and CO emissions.

Normal ignition timing that is the basis for ignition timing control when driving must occasionally be compensated to a slightly more advanced or retarded ignition timing due to other factors than just load and engine speed.