In May 1975 Mercedes presented the 450 SEL 6.9 – the new top model in the series and true successor to the 300 SEL 6.3. The powerful 6.9-liter V8 engine, developed from the highly successful 6.3-liter unit, achieved an output of 286 hp (210 kW) and maximum torque of 56 mkg. The hydropneumatic suspension with self-leveling – featured for the first time in a Mercedes-Benz passenger car – guaranteed the utmost in ride comfort. Other special equipment included in the standard specification for the top-of-the-range model were the central locking system, air-conditioning and a headlamp wash/wipe system. As was the case with its direct predecessor, the 450 SEL 6.9 proved an immediate success; although it was more than twice as expensive as the 350 SE, a total of 7,380 units were built during its four and a half year production period.