Originally displacing 4.5 L and featuring a single overhead camshaft design, Porsche enlarged and revised the engine in 1980 onwards. The engine was now a 4.7 L V8. European versions debuted with 221 kW; 296 hp (300 PS), and were upgraded to 228 kW; 306 hp (310 PS) for the 1984 model year. 1983 was the first time the North American market got the 928 S version. Specs are for the North American market.