M277

By 2014 every other petrol engine Mercedes-Benz sold had moved to four valves per cylinder and direct injection. The V12 refused. For the W 222 S 600 the 6.0-liter biturbo kept the single camshaft per bank, the three-valve head and the port injection it had carried over from the M275, on the reasoning that the layout was already quiet and already smooth. Almost everything beneath was renewed: an all-aluminum crankcase, a forged steel crankshaft, forged pistons, sodium-filled hollow exhaust valves and a twin-spark coil for every cylinder, with 830 N·m standing by from 1,900 rpm.

This was the civil half of a pair. AMG took the same architecture for the M279, added larger turbochargers and reworked heads and found 630 PS for the S 65 and the Maybach S 650, leaving the M277 the unhurried work in the S 600, the Mercedes-Maybach S 600 and the Pullman. Stop/start, a seven-speed automatic and a fifth less fuel than its predecessor bought the twelve one more model cycle and a Euro 6 certificate. In 2017 the S 600 gave way to the AMG-engined Maybach, and the softer V12 was finished.