The M3 CS's powertrain is identical to that of the Competition xDrive, though output is bumped to 543 hp. The inclusion of the xDrive all-wheel-drive system stands in contrast to the rear-drive setup of the M4 CSL. Because xDrive is so efficient at putting power down to launch the car off the line, the M3 CS's zero-to-60 mph sprint time of 3.2 seconds is actually 0.4 second quicker than the M4 CSL despite the sedan being roughly 300 pounds heavier. At the same time, a carbon-fiber roof, carbon-fiber bucket seats and a CFRP hood, spoiler and interior trim all add up to a touted 75 pounds of weight savings compared to the M3 Competition xDrive.
BMW offers two brake options: the standard M Compound rotors, or a set of carbon-ceramic brakes that should resist fade on track days. They sit inside forged wheels (19 inches up front, 20 inches at the rear) wrapped in your choice of a traditional high-performance road tire or, as a no-cost option, Michelin Pilot Sport Cup 2s.
BMW engineers have also included a titanium exhaust and retuned the stability control system, adaptive dampers and steering to give the CS a unique and presumably harder-edged sound and feel compared to other M3 models.