The N73 was the world's first production V12 engine to use gasoline direct injection.
[1] Compared with its M73 predecessor, the N73 has dual overhead camshafts, double-VANOS (variable valve timing) and valvetronic (variable valve lift).
The VANOS units were designed as integral components of the chain drive, and the adjustment ranges are 63 degrees for the intake camshaft and 60 degrees for the exhaust camshaft.
The N73 engine also has variable valve lift (valvetronic), which varied intake valve opening lift from 0.30–9.85 mm (0.01–0.39 in), according to engine speed and load.
Each cylinder head has a valvetronic assembly – including a motor, control module and position sensor.