The E90 is the currently available generation, which debuted for the 2006 model year,[citation needed] and is available as the sedan (E90), wagon (E91), coupe (E92), and coupe cabriolet (E93). It is completely re-engineered from the E46, including changes to engines, transmission, the passenger compartment, suspension technology, as well as a host of high-tech features and options. The coupé/cabriolet body is now its own design and no longer derived from the sedan minus two doors unlike its predecessors, being longer and narrower than its E90 counterpart. Major features include Comfort Access, bi-Xenon adaptive headlamps, Active Cruise Control, and Active Steering. The lineup received a mid-generational facelift for the 2009 model year.
Currently, four engine options are offered, two being part of the new ‘N’ series of BMW inline engines featuring a host of new technologies. Technological innovations such as lightweight magnesium/aluminum construction, electric water pump, Valvetronic (steplessly variable valve lift), and Double-VANOS steplessly variable valve timing contribute to produce a lighter and more powerful motor than its predecessor, but yield a 15% increase in fuel economy. The E90 also marks BMW’s return to turbocharging with the introduction of the BMW 335. The N54 engine produces 300 bhp (224 kW; 304 PS) and 300 lb·ft (410 N·m) torque.The E90 series also marks another first for BMW—a retractable hardtop convertible.