Subaru Impreza WRX STI.

Subaru of America introduced a new 4-door version of the Subaru Impreza WRX STI performance flagship model. This will be the first time that the Subaru Impreza WRX STI has been offered in two body styles (5-door and 4-door). In addition to the new styling, the 2011 WRX STI features significantly revised suspension tuning and lighter 18-inch wheels for even sharper handling.
The Subaru Impreza WRX STI has been a recipient of continuous improvement since its introduction. Most recently, the 2010 WRX STI Special Edition previewed some of the suspension enhancements now migrated to the 2011 Subaru Impreza WRX STI. Thorough and painstakingly detailed chassis development, including testing on Germany's famed Nurburgring racetrack, has resulted in the best-handling Impreza WRX STI models Subaru has ever offered.

"The continuous evolution and development of the Subaru Impreza WRX STI is driven by the strong, loyal and vocal support from thousands of enthusiastic owners of this exciting high-performance vehicle," said Tom Doll, executive vice president and COO of Subaru of America, Inc. "The 2011 Subaru Impreza WRX STI 4-door will expand the appeal of this iconic performance model to a wider range of driving enthusiasts."
New Designs for 2011
In front, the 2011 WRX STI models feature sharpened bumper corners and wider, blacked-out fog lamp nacelles to accentuate the "wide and low" profile. A jutting lip spoiler with three-dimensional detailing emphasizes the cars' sporty intent. The newly designed front grille with black base and blacked-out Subaru wing highlights the headlights' shape to give the entire front end a more powerful appearance, accentuated by larger grille and bumper intake openings.
For the 4-door models, newly designed wider rear fenders are stretched out on the side beyond the tail lamps, accentuating a look of power and stability. The new design details contribute to an improved drag coefficient.
New Chassis Tuning for 2011
The Subaru Impreza WRX STI was already a highly optimized performance machine. Specific chassis tuning. Aluminum front lower L-arms reduce unsprung vehicle weight. Major chassis tuning changes include a lowered ride height and new pillow-ball bushings in front and stiffer bushings for the rear subframe that supports the double-wishbone suspension - these improve camber and toe stiffness.
Both the front and rear suspension systems employ higher-rate springs and thicker front and rear stabilizer bars than the 2010 model: 21 mm vs. 20 mm in front and 19 mm vs. 18 mm in rear. Spring rates have increased by 15.6 percent in front and 53 percent in the rear.
New standard 18-inch aluminum wheels feature high-luster paint and weigh 17.6 lbs. less than the previous standard wheels. The optional 18 x 8.5-in. BBS® forged aluminum-alloy wheels, which further reduce unsprung vehicle weight, are highlighted by silver high-luster paint for 2011.
Exclusive to the Subaru Impreza WRX STI, the Brembo Performance Brake System uses ventilated 4-wheel Super Sport anti-lock (ABS) disc brakes with Electronic Brake-force Distribution (EBD). Super Sport ABS can control the braking forces at each rear wheel independently, which optimizes braking ability during hard cornering to help reduce understeer.
The Ultimate Performance Subaru
The 2011 WRX STI continues as the ultimate-performance Subaru with its high-boost 305-hp turbocharged/intercooled 4-cyl. Boxer engine and 6-speed manual transmission. The STI also features Multi-Mode Driver Controlled Center Differential (DCCD) version of Symmetrical All-Wheel Drive with three "Auto" modes, as well as a manual mode with six driver-selectable differential locking settings.
The Subaru Impreza WRX STI is equipped with advanced dynamic control systems, as well: the Multi-Mode Vehicle Dynamics Control (VDC) stability and traction control system is standard and features a track performance-optimized mode; Subaru Intelligent Drive (SI-DRIVE) technology allows the driver to tailor the car's driving characteristics by choosing from among three selectable modes - "Intelligent," "Sport" and "Sport Sharp" - using a rotary dial on the center console.

The 2011 Subaru Impreza WRX STI models arrive in Subaru dealerships in late summer 2010.