It was introduced as a replacement for the N55 engine back in 2015 ... It's a 3.0-liter twin-scroll turbocharged straight-six ...

The upgraded ALPINA version of the N55 in the B4 S Bi-Turbo put out 440 ... direct injection, a closed-deck design for its crankcase, and aluminum alloy pistons coated with Grafal, a screen ...