The BMW M4 CS (2018) sits between the M4 Competition Package and the hardcore GTS, running the S55 at 454 hp (460 PS) and 442 lb-ft (600 N·m) — BMW's own US press materials list this as 29 hp over the standard M4 Coupe. It's dual-clutch only, with a carbon-fiber hood, roof and trunk lid, Michelin Pilot Sport Cup 2 tires standard, and BMW's adaptive M suspension with an Active M differential.

Despite the carbon panels, the CS is not actually lighter than a standard DCT M4 — BMW's own published curb weights put it about 95 lb (43 kg) heavier, since its added equipment (bigger brakes, sport suspension hardware, wider tires) outweighs the panel savings. It is lighter than an equivalent M4 Competition Package car specifically, by about 77 lb (35 kg); the CS's case is a sharper factory setup and a limited run, not outright weight loss over the base car.