Brief History of the Porsche 928 from 1978 - 1995 for more info choose European or USA Year Model Disp. Power Notes 1978-1982 928 4.5l 219 hp Electronic fuel injection debuts in 1980. 1981 begins 928 S production in Europe with a 300 hp 4.7l engine. U.S. receives Competition Package w/ S spoilers but not the motor. 1983-1984 928 S 4.7l 300 hp Euro spec. 1983-1984 928 S 4.7l 234 U.S. spec. 1985-1986 928 S 5.0l 288 hp New DOHC U.S. motor with 4 valves per cylinder. Euro S continues with 300 hp SOHC 4.7l motor. 1987-1991 928 S4 5.0l 316 hp First of the new body style. "S4 brakes": 11.97" brake rotors w/ 4-piston calipers introduced on late '86 models. Difficult to adjust dual-disc clutch replaced with single disc unit. 1989-1991 928 GT 5.0l 326 hp Computer-controlled limited slip differential derived from technology pioneered on the 959. 5-speed only. Tightest 928 suspension. 1992-1995 928 GTS 5.4l 345 hp 1992 only available in Europe after mid-year. "GTS brakes": 12.68" rotors with still larger 4-piston calipers.