From the 924's release in 1975 Porsche began a long development program of the model. In 1978 the Turbo edition was added to the range although this was withdrawn from production in 1982. In 1985 the 924 was replaced by the 924S using a de-tuned 2.5-litre 944 engine. This is a book of contemporary road and comparison tests, new model introductions, technical and specification data, development, racing, buying second hand, long-term tests. Models covered include:- Carrera GT, Le Mans, Lux, 5-speed, 924S, Supercharged, Automatic, Turbo.