What do we, more specifically The Colonel remember of the 6.3?
Back in the day a 300SEL was the top of the line version of the S Class, while the numerals on the right hand side of the trunk added increased cachet.
The 6.3 was the equivalent of an S65...today. It was a serious hot rod from Stuttgart.
Those were the days when Mercedes-Benz was emerging from the vestiges of WWII, the plant in Sindelfingen was a previous airplane production facility. Especially in North America M-B needed a more forceful identity than simply diesel and 6 cylinder cars.
In typical M-B fashion the car was over engineered, with rudimentary convenience features, stiff Teutonic leather, the 4.5 V8 had morphed into the 6.3 from of the 600. With the 6.3 it was fashionable to remove the 6.3 from the trunk.
To uphold the Teutonic tradition of the day, which implied that if it was an expensive car it should cruise effortlessly at ridiculously high speeds on the autobahn. This was accomplished with a low numerical rear axle ratio, and usually a second gear start from the transmission.
Until you stopped, literally shifted the transmission to 1st gear, and throttle up it was not obvious how fast this car could accelerate. The transmission would bang through the shifts like an old school Hydra Matic in a truck.
Back in the day corrosion protection was rudimentary, and in Canada by the time these cars were 10 years old, there were serious corrosion issues, the air suspension was delicate, and the 6.3 consumed prodigious amounts of gasoline.
It was a landmark, benchmark car with superlative performance, while corroding and requiring expensive maintenance.
Here is Jay Leno driving and sharing his memories of the 6.3...