Model story

In 1964, Mercedes-Benz launched the top-of-the-line W100 sedan, powered by a SOHC 6.3-liter V8 engine. However, the sedan's hand-assembly and very high price limited sales, while its size and weight compromised performance. In 1966, company engineer Erich Waxenberger transplanted the large V8 into a production W109, creating the first Mercedes-Benz Q-Car.

Despite the W109's size, the automaker claimed a 0-100 km/h acceleration time of 6.3 seconds. Series production began in December 1967. The 300SEL 6.3, considered the fastest production sedan (top speed 229 km/h), held this title for many years. Strict West German laws and product labeling regulations led to these figures being understated. The 6.3 also introduced a new numbering system: the model name described the parent model, while the engine displacement was separate. This nomenclature was used by Mercedes-Benz until the introduction of the class system in 1993.

The Mercedes-Benz 300 SEL 6.3 was a large luxury car built by Mercedes-Benz from 1968 to 1972. It featured the powerful 6.3-liter M100 V8 from the luxurious 600 sedan, which was installed in the six-cylinder Mercedes-Benz 300 SEL. The result was a nearly two-ton sedan with performance comparable to that of most sports cars and American muscle cars of the era. At the time of its launch, it was the fastest four-door car in the world.

The car was developed as a private car in 1966 by company engineer Erich Waxenberger. His principle was simple: He took the powerful 6.3-liter V8 engine of the Mercedes-Benz M100 from the luxurious 600 sedan and installed it in the regular Mercedes-Benz S-Class W109, which at the time was only equipped with 6-cylinder engines. The result was a nearly two-ton sedan with performance comparable to that of most sports cars of the time. It is said that when Rudolf Uhlenhaut was invited to test drive the prototype, he opened the hood at the first red light to see how the large engine and its ancillary components had been squeezed in.

Surprisingly, the rather conservative company launched the car at the Geneva Motor Show in March 1968 to better utilize the production facilities for the M100 engine. The 6,500 units of the 6.3 far exceeded the 2,700 units of the 600.

What set this car apart from its contemporaries in the late 1960s, however, was its speed of over 200 km/h (124 mph) with five passengers in the Paul Bracq-designed body. Later, the company also installed new, smaller V8 engines in the W109 series. The 300SEL 4.5 was only available in the USA, while the 280 SE 3.5 Coupé could also be ordered in Europe.

In 1975, the Mercedes-Benz 450SEL 6.9 was introduced as the successor to the 300SEL 6.3, with larger displacement, modified equipment, and more power.

Air suspension, ventilated disc brakes on all four wheels, power windows, central locking, and power steering were standard equipment. Air conditioning, a power sunroof, desks (for the rear seats), window shades, an audio cassette player, and rear seat reading lights were available as options.

6,526 units of this vehicle were produced.