The BMW 3.0 N55 engine only came a few years later than the 3.0 N54, and both had much the same power output, so what are the differences between the two?

Ever since turbochargers entered mainstream use in road-going, gasoline-powered cars — dating back to at least the first Porsche 930 Widowmaker of the 1970s — automakers have come up with all kinds of ...