The Z4 is available as either the sDrive30i, or the sDrive35i. Power for the sDrive30i comes from a 255-hp 3.0-liter inline six-cylinder engine. The sDrive35i is powered by a twin-turbo, 300-hp 3.0-liter inline six-cylinder engine. Both models come standard with a six-speed manual transmission. An optional six-speed automatic transmission is offered on the sDrive30i, while an advanced double-clutch seven-speed automatic transmission is available on the sDrive35i. Standard features include Driving Dynamics Control which allows the driver to change the vehicles characteristics between normal, sport, and sport+ mode, adaptive brake lights, and a two-piece lightweight-aluminum hardtop.For 2010, HD Radio has been added as standard equipment.