The Impreza small-car family spans a wide range of the small-car market, starting with the rather basic, economical Impreza 2.5i, and ranging up to the rugged Outback Sport, sporty WRX and topping out with the high-performance STI. Both 5-door hatchbacks and 4-door sedan bodystyles are available. Both of the sportier models in the lineup, the STI and WRX, get heavily revised sheetmetal this year, with flared-out wheelwells and fenders that give these models a more macho look. Front and rear bumpers and air dams are also reshaped, while larger wheels and tires are positioned slightly outward for a better stance. A 2.5-liter horizontally opposed, or "boxer" 4-cylinder engine is standard on 2011 Subaru Impreza 2.5i and Outback Sport models. It makes 170 horsepower and can be paired with either a 5-speed manual transmission or 4-speed automatic. Like all models in the Subaru lineup, it comes with standard all-wheel drive. With a strut-type front suspension and double-wishbone rear setup, the Impreza has a suspension layout that affords a larger trunk or cargo area while providing sporty handling and door ride comfort. All Imprezas come with quick-ratio rack-and-pinion steering for a turning circle of less than 35 feet. Four-wheel anti-lock disc brakes are also standard. The relatively unique horizontally opposed engine design also provides improved handling compared to some other small-car layouts. While the 2.5i and Outback Sport provide adequate acceleration, the turbocharged, 265-hp, 2.5-liter engine in the WRX provides the quick, responsive feel of a sports car in the same practical package as the standard Imprezas. For even more power and performance, the WRX STI steps up to a 305-hp version of the same engine. Neither of these performance models is offered with an automatic transmission. WRX models come with a special viscous-coupling all-wheel drive system that can either split power 50/50 or send it to the wheels with more available traction. STI models get a special rally-bred Multi-Mode Driver Controlled Center Differential (DCCD) version of the all-wheel drive system that reverts to a 41/59 front/rear torque split. It's a serious performance setup, with a mechanical limited-slip differential, torque-sensing front differential and limited-slip rear. It has the ability to dial up the degree of center-diff lockup via a switch on the center console. Three auto settings allow novices to vary the feel of the car, or adjust for weather conditions, while a manual setting calls out to the experienced rally or autocross drivers. The Impreza includes Subaru's VDC stability control system. All Imprezas come with Brake Assist, to help provide peak boost in emergency braking, Start Assist, to help start on hilly inclines and front side and side-curtain airbags. Impreza sedans feature a surprisingly roomy trunk and, Subaru claims, can accommodate three tour-sized golf bags. Hatchbacks have slightly less cargo space, but the rear seats fold fully forward in both body styles. Backseat space is about the same in either model--just adequate for 6-footers, while in front much taller folks will be happy. All Impreza models now get a new audio system with iPod connectivity, USB, an auxiliary input, iPod controller and Bluetooth hands-free interface. STI models also get special badging throughout, plus aluminum-alloy pedal covers, single-piece sport seats and a leather-wrapped steering wheel. All models have tilt-and-telescopic steering wheel adjustment. Automatic climate control is standard on the STI, while the navigation system is optional on most of the lineup.