This comprehensive service manual provides detailed technical specifications for the 1985-1989 Porsche 928 S and 928 S4 models. It is designed to be a valuable resource for anyone looking to maintain, repair, or restore their vehicle. This manual, used by experts and technicians alike, offers model-specific information, ensuring accurate and reliable repairs. It contains detailed information on all aspects of your Porsche, including the engine, transmission, suspension, brakes, electrical system, and more. You will find detailed diagrams, illustrations, and step-by-step instructions to guide you through any repair or maintenance task. This manual is your ultimate resource, empowering you to perform repairs yourself and avoid potentially costly and unreliable repair shops. With its in-depth content and user-friendly format, this manual is an indispensable tool for any 928 S or 928 S4 owner.

The Porsche 928 S and 928 S4 were luxury grand touring cars produced by the German automaker Porsche between 1985 and 1989. The 928 S, launched in 1985, marked a significant evolution of the original 928, featuring a revised front end design with integrated fog lamps, a redesigned interior with improved ergonomics and creature comforts, and a powerful 4.5-liter V8 engine. The engine, rated at 316 horsepower, offered a thrilling driving experience while providing the luxury and comfort expected of a grand touring car. The S model also boasted a sophisticated suspension system that balanced performance with a comfortable ride. The 928 S4, introduced in 1987, was a further refinement of the 928 line. This model featured a larger, 5.0-liter V8 engine boasting 320 horsepower, coupled with a refined engine management system and improved aerodynamics, resulting in better fuel economy and even more impressive performance. The 928 S4 also introduced several technological advancements, including a Bosch Motronic engine management system, anti-lock brakes (ABS), and power steering as standard features. Other noticeable changes included a revised rear end design with integrated taillights and a more pronounced rear spoiler. The S4 also came with a new set of wheels, contributing to its overall aggressive aesthetic. Both the 928 S and 928 S4 offered an unparalleled blend of performance, luxury, and comfort, solidifying their position as iconic grand touring cars of the 1980s.