This was MY manual from the 80s when I worked for a Porsche dealer in London , so it’s used but it’s all there The Workshop Manual/Service Information Technology Porsche 928 S4 from July 1987 is an original literature product by Porsche. This manual, tailored for English-speaking enthusiasts of the Porsche 928 S4 model from the 1980s, provides essential service and repair information in portrait format. It is a valuable resource for those looking to maintain or repair their vintage Porsche vehicles with expert guidance from the manufacturer.