Subaru introduced the new 2011 4-door Impreza WRX STI to join its 5-door performance flagship model with revised suspension tuning and lighter 18-inch wheels. The WRX STI has a high-boost 305 horsepower turbocharged/intercooled 4-cylinder boxer engine mated to a 6-speed manual transmission with the Multi-Mode Driver Controlled Center Differential version of Symmetrical All-Wheel Drive with three "Auto" modes, as well as a manual mode with six driver-selectable differential locking settings.
