Guys, the owner's manual claims that all W126(up until 1989?), W123, W124, whatever, stop in exactly 165 feet. That is not true at all. The later W126 ('86 +) had stronger braking systems with massive front rotors and brakes. The later W124's did too.
The chart listed in the back of the manual is not meant to be accurate. It is just showing what would happen if you lost power to the brakes. Be it partial failure, or complete failure.
Maybe I'm crazy, but the post '86 S-Class vented rotors look like they're about 13 inches. They are really massive discs! Pretty heavy too.
BTW, thanks to the "wonderful" stopping power of the W126, I snapped the front swaybar off of mine like a twig while trying to avoid a FFC(Friendly Forest Creature).
As far as side collisions go. Um....Side bags and curtains are certainly nice. In the case of the W126, its solid enough to hold its own if a train collided with it(seriously). I'd just have to see it coming and brace for impact. Otherwise the B-Pillar's color would suddenly change from either parchment, palomino, or blue to a rather spotty garnett red.
:p