At its debut, the 996 featured the most significant change from the classic 911 series: a water-cooled engine replacing the previously air-cooled engine. Progressively more stringent emissions and noise regulations, environmental concerns, a higher expectation for refinement and the need for a high-performance 4 valve per cylinder engine made the switch necessary. Other major changes include a completely new platform having a sleeker body with a more raked windshield, and a re-designed interior along with new "fried egg" shaped headlamps (so called due to the amber coloured turn signals) instead of previous "bug eye" headlamps.
