The M5 CS (2022) is the lightest, hardest, and most powerful F90, running the S63 at its highest 627 hp tune and shedding about 256 lb (116 kg) versus the standard M5. At launch it was the most powerful series-production BMW M car built.

The weight saving comes from carbon-fiber-reinforced plastic (CFRP) body panels — hood, front splitter, mirror caps, rear spoiler lip, and rear diffuser, worth about 70 kg of the total versus the Competition — plus standard M Carbon-ceramic brakes, lightweight M Carbon bucket seats front and rear, a lighter exhaust with less sound insulation, and deletion of the rear center seat, making the CS a strict four-seater.