The BMW M4 is a high-performance version of the BMW 4 Series automobile developed by BMW's motorsport division, the BMW M GmbH. Part of the renumbering that splits the 3 Series coupe and convertible models to the 4 Series (to further differentiate it from the 3 Series), the M4 replaced the M3 Coupe and Convertible models. Upgrades over the standard BMW 4-Series include: a very powerful and responsive, twin turbocharged engine; improved handling, suspension, and braking systems; aerodynamic body enhancements; interior/exterior accents with the tri-colour "M" (Motorsport) badging; the significantly reduced weight compared to the standard 4 series and its predecessor with an all-new stiffer chassis and extensive use of carbon fiber, especially the roof of the car.