It was a car that it wasn’t planned and it was the result of a particular Mercedes-Benz engineer, Erich Waxenberger.
He just took the biggest V8 from the shed and slammed it under the hood of a regular 300 SEL.

When the Mercedes-Benz chief engineer tested the car, it is said that at a stoplight he jumped out of the car and looked under the hood to see how the big V8 was installed. That gave him confidence and propose the series model. The production model was shown at the Geneva Motor Show in 1968 and it was a sensation. Even if the price tag was high for that era (DM 10.000 – USD 5.000), the customers came to ask for more and more. It was twice as much as a 300 SEL 280. According to Mercedes-Benz’s official data, 6526 units were produced before the end of the series in 1972.

The exterior look was very close to the standard 300 SEL with a smaller engine. There were a few clues that the car was something different. The 6.3 could only be recognized by its wider tires, double halogen headlights, and additional high-beam headlights.

At the time of launch, it was the fastest four-door car in the world and it kept that title for many years. For the suspension, it featured a self-leveling system for the rear axle to keep the same level regardless of the load, four disc brakes, power windows and locks, and power steering.