What is engine downsizing and what technologies enable it?

Engine downsizing replaces larger naturally aspirated engines with smaller turbocharged or supercharged engines that produce equivalent power but better fuel economy at light loads. Key enabling technologies include turbocharging/supercharging for power recovery, direct injection for knock resistance and efficiency, variable valve timing for broad powerband, advanced engine management for boost control, and stronger materials for higher cylinder pressures. Typical downsizing reduces displacement by 30-50% while maintaining performance.