levelling air suspension. In 1967, the 250S and 250SE were replaced by the 280S and 280SE. The 300SE was deleted and the 300SEL received the 280’s new 2.8-litre engine. The 300SEL 6.3 was the most exclusive and extravagant Mercedes money could buy, except for the 600. The 6.3 engined V8 300SEL was launched in March, 1968: it used the engine first seen in the 600 model, which equipped the lighter bodied W109 for a claimed headline grabbing 0-60 mph (096 km/h) time of 6.3 seconds. US ...