The BMW 123d is the world's first four-cylinder engine with Variable Twin Turbo.
Two different-sized turbochargers are deployed sequentially to dispense extra power
right across the rev range. At low revs, the small turbocharger works on its own
to provide instantaneous throttle response. Third-generation common rail injection
ensures exceptional performance (up to 150 kW/204 hp) in hand with unbeatable fuel
consumption levels (ca. 5 l/100 km). And thanks to the engine block now being made
solely of aluminium, weight is reduced by an enormous 20 kg.