The 1987-1991 Porsche 928S4

Overview

The 928S4 elevated the grand touring platform during 1987-1991 through displacement expansion to 5.0 liters and power escalation to 316 horsepower, establishing the V8 as a truly muscular powerplant. This model represented Porsche's comprehensive refinement of the 928 platform, incorporating updated styling, advanced electronic systems, and powertrain enhancements that positioned the vehicle competitively against contemporary performance sedans. The S4 designation signified fourth-generation specifications, reflecting the model's evolutionary position within the 928 family. The 928S4 attracted customers seeking the ultimate grand touring experience with genuine performance credentials and premium prestige.

The 928S4 philosophy centered on extracting maximum performance from the V8 grand touring platform through substantial displacement enlargement and sophisticated electronic management systems. Porsche's engineering approach emphasized responsive power delivery, comprehensive electronic systems managing throttle response and traction, and refined component selection supporting the heightened performance envelope. The displacement increase from 4.7 to 5.0 liters provided substantial horsepower escalation that established the 928S4 as genuinely competitive with contemporary high-performance sedans from luxury manufacturers. The 928S4 represented mature V8 grand touring positioning, incorporating years of accumulated engineering refinement.

Engineering & Development

The 928S4 naturally-aspirated 5.0-liter V8 engine employed water-cooling with cast-iron block and aluminum cylinder head construction. The 316-horsepower output, with peak torque of 317 lb-ft, reflected the displacement advantage and optimized combustion geometry. Bosch fuel injection with advanced electronic engine management provided efficient combustion control and responsive throttle characteristics across the performance envelope. The four-valve-per-cylinder design improved combustion efficiency and high-revving capability. The longitudinal front mounting with transaxle transmission maintained the weight distribution grand touring operation required.

The four-speed automatic transmission incorporated improved shift logic and electronic controls managing gear selection based on driving conditions. Enhanced suspension geometry with multi-link configurations and sophisticated damping provided refined ride quality while supporting the elevated performance envelope. Upgraded brake systems featuring larger ventilated rotors and improved friction materials addressed the substantial stopping demands. The unibody steel construction received comprehensive reinforcement throughout, supporting the powertrain's specifications. Advanced electronic systems including traction control and anti-lock braking enhanced safety and performance characteristics. Comprehensive interior appointments reflected the luxury grand touring character.

Market Variants

The 928S4 appeared throughout its 1987-1991 production window with the 5.0-liter V8 engine and four-speed automatic transmission. Production extended with approximately 21,000 units manufactured, representing continued demand for the grand touring platform. Geographic distribution favored luxury markets worldwide, with strong demand in North America and Western Europe. The 928S4 attracted customers seeking performance escalation and comprehensive electronic integration within the grand touring segment.

Contemporary collector enthusiasm for 928S4 examples reflects appreciation for the V8's substantial power delivery and sophisticated engineering.

Significance

The 928S4 represented the comprehensive refinement of the 928 platform, providing displacement-enlarged V8 performance coupled with advanced electronic systems that established the engine family's sophistication and capabilities. The model proved that large-displacement V8s could deliver substantial performance while maintaining thermal management and reliability grand touring operation required. The 928S4's commercial success validated customer interest in performance-oriented grand touring positioning.

The platform established the 928S4 as the ultimate expression of first-generation 928 development, incorporating comprehensive engineering refinement across all systems. The model's technical achievement positioned the 928 family competitively against contemporary high-performance sedans, validating Porsche's grand touring market participation. The 928S4 marked an important evolutionary point, demonstrating mature engineering execution within the grand touring segment.