How do ignition advance requirements change with engine load?

Ignition advance requirements increase with engine load due to the need for optimal combustion timing to maintain performance and efficiency. Under higher load conditions, the engine requires more power, which necessitates an earlier ignition timing to ensure that the fuel-air mixture ignites at the right moment for maximum pressure during the power stroke. Conversely, at lower loads, ignition timing can be retarded to prevent knocking and improve fuel economy. Thus, tuning the ignition advance based on load helps balance performance and efficiency.