The 6.3
Back in 1964, Mercedes-Benz launched its top-range W100 limousine which featured a dry-sump 6.3 litre V8 engine. However the limited hand-assembly of the limo and its very large price tag limited the spread of the car, whilst the size and weight affected performance. In 1966 company engineer Erich Waxenberger transplanted the big V8 into a standard W109, creating the world's first Q-car.
Despite the large size of the W109, the automaker claimed 0-62 mph (0–100 km/h) time of 6.3 seconds. Full-scale production began in December 1967. Claimed as the fastest production sedan (top speed of 229 km/h), the 300SEL 6.3, held this title for many years. West Germany has stringently-applied trade description laws and figues resulted in these figures being under quoted. The 6.3 also introduced a new naming scheme, where the model name described the parent model and the engine displacement was separate. This nomenclature was used by Mercedes-Benz until the introduction of the class system in 1993.
Read more about this topic: Mercedes-Benz W108