🏷️ Basic Information Identification Make: Porsche Model: 928 Model Variant: S4 Applicable Years: 1987, 1988, 1989, 1990, 1991 Codes Internal Chassis Code: Type 928 Engine Code Prefix: M28 👋 Introduction Market Position Positioning: High-performance GT coupe, positioned as a luxury sports car with advanced engineering. Competitive Analysis Competitors: Ferrari 400i/412, Aston Martin V8 Vantage, Maserati Quattroporte Key Features Design Philosophy: Front-engine, rear-wheel drive transaxle layout for optimal weight distribution, V8 engine, sophisticated chassis dynamics. Unique Selling Points: Comfortable Grand Tourer with sports car performance, advanced engineering for its era, distinctive styling. 📋 Manual Details Coverage Areas Coverage Scope: Comprehensive service, repair, overhaul, and maintenance Page Count Estimated Page Count: Extensive (specific count not provided, but described as 'complete' and 'many') Manual Type Type: Workshop Service Manual / Repair Manual Language Language: English Format Format: PDF (Electronic Delivery) 📖 Manual Coverage Systems Covered Engine: Yes (including disassembly, overhaul, tuning, lubrication) Fuel System: Yes Ignition System: Yes Lubrication System: Yes Exhaust System: Yes Electrical System: Yes Bodywork: Yes Transmission: Yes (including disassembly and overhaul) Procedures Included Maintenance: Routine maintenance and servicing procedures Repair: Diagnostic and repair procedures for troubleshooting Overhaul: Detailed overhaul procedures for major components Installation: Removal and installation procedures for components and assemblies Disassembly Assembly: Detailed procedures for assemblies and disassemblies Technical Depth Depth: Advanced diagnostics, complete engine and transmission rebuilds, proprietary component integration Target Audience: Primarily for mechanical technicians familiar with BRP products and general automotive practices 📊 Manual Specifications File Format Format: PDF Delivery: Fast and Free Electronic Delivery via Email Print Quality Printable: Yes Binding Type Binding: Not Applicable (Digital PDF) Paper Type Paper: Not Applicable (Digital PDF) Special Features Warnings Cautions Notes: Emphasizes specific information via WARNING, CAUTION, NOTE designations Special Tools: References and illustrates Porsche special tool numbers where required ⚙️ Engine Specifications Primary Engine Type: V8, naturally aspirated Displacement: 5.0 Liters (4957 cc) Bore X Stroke: 97.0 mm x 84.0 mm Compression Ratio: 10.0:1 Valve Train: SOHC, 2 valves per cylinder Performance Horsepower SAE Net: 310 hp @ 6000 rpm (approx.) Torque SAE Net: 330 lb-ft @ 4500 rpm (approx.) Fuel System Induction: Bosch L-Jetronic fuel injection (LH-Jetronic for later S4 models) Fuel Type: Premium Unleaded Gasoline Lubrication Oil Capacity With Filter: Approx. 10.5 US quarts (9.9 Liters) Recommended Oil Viscosity: 5W-40 or 10W-40 (check manual for specific climate recommendations) 🔧 Transmission Standard Type: 4-speed Automatic Transaxle (G97.00/01) Optional Type: 5-speed Manual Transaxle (G97.76 - less common) Features Layout: Rear transaxle (engine front, transmission rear) Fluid Automatic Transmission Fluid Type: Dexron III (or equivalent, consult manual for Porsche P/N) Manual Transmission Fluid Type: Gear Oil SAE 75W-90 (GL-5, consult manual for Porsche P/N) 📐 Dimensions Exterior Length: 4655 mm (183.3 in) Width: 1775 mm (69.9 in) Height: 1282 mm (50.5 in) Wheelbase: 2433 mm (95.8 in) Weights Curb Weight Approx: 1600 kg (3527 lbs) for automatic Gross Vehicle Weight Rating: Approx. 2040 kg (4497 lbs) 🛡️ Safety Features Ratings Crash Test Data: ERA: Limited structured crash data available for this era; focus on Porsche's engineering for occupant protection. Active Features Braking System: Four-wheel disc brakes with ABS (Anti-lock Braking System) Suspension: Independent suspension with optional self-leveling and ride height control (M475) Passive Features Airbags: Driver's side airbag standard Seat Belts: Three-point inertia-reel seat belts 💡 Technology Features Infotainment Audio System: Factory premium sound system, often with cassette player and graphic equalizer. Upgrades common. Climate Control: Automatic climate control with A/C Driver Assistance Cruise Control: Standard Connectivity Connectivity Features: Limited by era; typically no integrated Bluetooth or smartphone connectivity from the factory. Other Features Lighting: Pop-up headlights 🔧 Maintenance Service Intervals Oil Change: Every 5,000 - 7,500 miles or 12 months (refer to manual for exact specification) Timing Belt Replacement: Every 30,000 - 50,000 miles or 4-5 years (critical component, refer to manual for exact interval and procedure) Fluid Specifications Coolant: Porsche approved G48 (Ethylene Glycol based) coolant mixed 50/50 with distilled water Brake Fluid: DOT 4 or DOT 5.1 (refer to manual for specific recommendation and flush interval) Known Issues Common Problems: Timing belt failure (catastrophic engine damage), electrical gremlins, fuel distributor issues, radiator leaks, A/C system problems. Maintenance Importance: Due to the complexity and performance of the 928 S4, adherence to a strict maintenance schedule and using quality parts is paramount. 📚 Vehicle History Brand Heritage Heritage: Porsche AG, renowned for sports car engineering and performance heritage. Model Evolution Evolution: The 928 was a departure from Porsche's rear-engine sports cars, introduced in 1978. The S4 variant, launched in 1987, represented a significant update with improved aerodynamics, more power, and enhanced comfort/features. Production Production Period: 1978-1995 (S4 variant primarily 1987-1991) Manufacturing Location: Stuttgart, Germany 🏆 Awards & Recognition Recognitions Era Recognition: While specific awards for the '87-'91 S4 are not prominently recalled, the 928 line was generally lauded for its engineering prowess and GT...