 Beginning in 1985, F-15C and D models were equipped with the improved P&W F100-PW-220 engine and digital engine controls, providing quicker throttle response, reduced wear, and lower fuel consumption.Starting in 1997, original F100-PW-100 engines were upgraded to a similar configuration with the designation F100-PW-220E starting.Beginning in 2007, 179 USAF F-15Cs would be retrofitted with the AN/APG-63(V)3 Active Electronically Scanned Array radar.