Initiated by Erich Waxenberger as an internal ‘spare-time’ project, the 300 SEL 6.3 was the first Mercedes of its kind. Waxenberger decided somewhere in 1966 to plant the huge M100 V8 engine of the Mercedes 600 into the much smaller 300 SE coupé. When development director Uhlenhaut agreed on this somewhat strange project, Mercedes though it would be better to introduce this engine into its 300 SEL model. They mounted a 4-speed automatic to the M100 and kept all the refinements and luxury of the regular SEL model. The car was launched at the 1968 Geneva Motor Show as the fastest limousine of the world. At that time a top speed of 229 KM/h was indeed spectacular, but the same as the already launched Maserati Quattroporte I and the Iso Fidia. However the 0-100 KM/h in 6.3 seconds was much faster than all these existing sport saloons. Mercedes produced the 300 SEL 6.3 until 1972. Apparantly Mercedes decided to go with the project because they wanted to make better use of the M100 engine production facilities. Well, mission accomplished, because it sold more than 6,500 units, compare to just 2,700 units of the 600.

Technical specification Mercedes 300 SEL 6.3: