The engine was a cast iron V8 with single overhead camshafts operating sodium-filled valves against hardened valve seats on each aluminium alloy cylinder head. Each hand-built unit was bench-tested for 265 minutes, 40 of which were under full load. Bosch K-Jetronicelectromechanical fuel injection was standard at a time when fuel-injected cars were uncommon. As in all Mercedes-Benz automobile engines, the crankshaft, connecting rods and pistons were forged instead of cast. The 6.9 l (6834 cc or 417 in³) power plant was factory-rated at 286 hp (213 kW) with 405 lb·ft (549 N·m) of torque helping to compensate for the 2.65 to 1 final drive ratio necessary for sustained high-speed cruising.
Shreveport, Louisiana, United States