2020 BMW X3, X4 M40i & M550i get huge power bump for the US – M550i’s 4.4L V8 makes 523 hp & 750 Nm!
BMW US has quietly released revised versions of the M550i, X3 M40i, and X4 M40i models for 2020, with each receiving sizeable gains in performance thanks to several hardware upgrades. Let's start …