Mercedes-Benz recently launched an updated version of its flagship S-Class sedan. That car packs a fresh 4.0-liter V8 with a flat-plane crank setup, doling out as much as 530 horsepower and 553 pound-feet of torque in the S580.
A flat-plane crank means less rotational mass and quicker revs, which helps equal more horsepower. But while the engine might be suited for Benz duty first and foremost, the AMG side of the family wants to make sure it's up to snuff before shoving it into the pumped-up snouts of its own vehicles.
