The Z4 is offered as one of three trims, sDrive30i, sDrive35i, or sDrive35is. 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. The new sDrive35is is powered by a twin-turbo, 335-hp 3.0-liter inline six-cylinder engine. Transmission choices range from a six-speed manual, six-speed automatic, or an advanced double-clutch seven-speed transmission. 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 2011, the sDrive35is has been added to the lineup. It features a 35-hp increase over the sDrive35i, adaptive M suspension, exterior mirror caps in matte oxide silver, and an exclusive aerodynamic package. All models receive Brake Energy Regeneration, additional upholstery choices, and paint finishes.