Subaru Introduces New 4-Door Impreza WRX STI for 2011
- First Time Subaru Performance Flagship Offered in Two Body Styles
- New WRX STI Four-Door with Wide-Body Design
- Retuned Suspension for Even Sharper Handling
Subaru Canada, Inc. (SCI) is announcing that for the 2011 model year the WRX STI is being 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 WRX STI has been a recipient of continuous improvement since its introduction. 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 WRX STI is driven by strong, loyal, and vocal support from thousands of enthusiastic owners of this exciting high-performance vehicle," said Shiro Ohta, chairman, president and CEO of Subaru Canada. "The 2011 4-door WRX STI will expand the appeal of this iconic performance model to a wider range of driving enthusiasts."
The 2011 Impreza WRX STI models are en route to Subaru dealerships now.
Performance Evolution
The 2011 WRX STI continues as the ultimate-performance Subaru with its high-boost 305-horsepower turbocharged/intercooled Subaru Boxer engine teamed with a 6-speed manual transmission and the exclusive Multi-Mode Driver Controlled Centre Differential (DCCD) version of Subaru's Symmetrical Full-time All-Wheel Drive system.
The WRX STI is equipped with advanced dynamic control systems, including Subaru Intelligent Drive (SI-DRIVE) and a Multi-Mode Vehicle Dynamics Control (VDC) system, which features a track performance-optimized mode. Hill Holder, featured on all Impreza models equipped with a manual transmission, can momentarily prevent the vehicle from rolling backward when being driven away from a stop on an incline.
All-New 4-Door Wide Body Design for 2011
The new WRX STI 4-door design is based on a "wide and low" concept that gives the car an aggressive road presence. Like the wide-body design already used for the 5-door WRX STI, the new 4-door WRX STI features the widened front and rear track dimensions of the 5-door model and wider, more pronounced front fenders and rear quarter panels. The design maintains a consistent flow from front to rear bumper, creating a distinctive identity and a sense of stability.
In front, the 2011 WRX STI models feature sharpened bumper corners 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 a black grille inset and blacked-out Subaru floating wing also signify the 2011 model and set off the headlights' shape to give the entire front end a more powerful appearance.
For the WRX STI 4-door sedan model, newly designed wider fenders are stretched out on the side more than the tail lamps, and this accentuates a look of stability. A striking high profile rear spoiler was exclusively designed for the STI 4-door. The new design details contribute to an improved drag coefficient, and the rear spoiler design contributes to stable high-speed handling and achievement of zero lift. The WRX STI 4-door features its own version of the polished stainless steel quad-tailpipe exhaust, with tailpipe diameter enlarged to three inches.
New WRX STI Chassis Tuning for 2011
The Subaru WRX STI was already a highly optimized performance machine. Changes in chassis tuning for 2011 reflect feedback from both owners and enthusiasts, as well as the brand's commitment to keeping this model at the peak of the segment's performance offerings. The fundamentals remain the same as before, but specific tuning results in reduced body roll, more neutral handling response and higher lateral-G capability.
The WRX STI delivers responsive handling along with everyday ride compliance. High-tensile-strength steel is used at key structural points and the suspension-mounting areas. Inverted struts used for the front suspension provide high bending resistance for quicker and more consistent performance under hard cornering. Aluminum front lower L-arms reduce unsprung vehicle weight.
Major changes to suspension tuning for the 2011 WRX STI 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 Enkei aluminum wheels feature high-luster paint and weigh 8kg less than the previous standard wheels. Dunlop SP600 245/40R18 summer performance tires are used with the standard and optional wheels.
SI-DRIVE Gives WRX STI Driver More Control
Exclusive to the WRX STI models, 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 centre console. SI-DRIVE alters vehicle performance characteristics by regulating the Engine Control Module (ECM) and by fine-tuning the Electronic Throttle Control system. With Intelligent mode selected, SI-DRIVE improves fuel efficiency and provides a more relaxed throttle response curve, making it useful for commuting in traffic, for example.
Sport mode provides quick throttle responses and powerful, linear acceleration, making it ideal for everyday sporty driving. In Sport Sharp mode, SI-DRIVE modifies the engine's electronic throttle mapping to deliver super-quick throttle response and put down the power sooner.
Multi-Mode DCCD All-Wheel Drive with Three-Mode Vehicle Dynamics Control
As before, the 2011 WRX STI is exclusively equipped with the Multi-Mode Driver Controlled Centre Differential (DCCD) version of Subaru Symmetrical All-Wheel Drive. The system employs planetary-type differential gears with a nominal 41:59 torque split. A mechanical limited-slip type centre differential augments an electronically controlled centre differential to enhance torque transfer performance. Sensor inputs that include steering angle, throttle position, RPM, lateral g, yaw, brake, ABS and wheel speed govern torque transfer response. A helical-type limited-slip front differential and a TORSEN(R) torque-sensing limited-slip rear differential optimize side-to-side power distribution, helping to prevent the inside wheels from slipping during cornering.
The DCCD AWD system features three automatic modes. Auto mode provides the best all-around performance for most drivers and circumstances, varying the front/rear torque distribution automatically via the limited-slip type differential (LSD) in response to vehicle acceleration, deceleration, steering angle, cornering force and wheel slippage. The Auto(-) mode makes less use of the centre limited-slip differential (less locking factor) and holds the torque bias to the rear more frequently, which yields more handling-oriented steering characteristics. For driving on slippery surfaces, such as gravel or snow, the Auto(+) setting tightens the LSD. In manual mode, DCCD offers six levels of centre differential locking, allowing the driver to vary the front-to-rear torque distribution (up to 50:50 maximum) to optimize AWD performance for varying driving conditions.
The Vehicle Dynamics Control (VDC) stability and traction control system is standard on all Subaru models. It is important to note that, in Subaru vehicles, traction control plays a second line of defence against wheel slip after AWD torque distribution. In contrast, some All-Wheel Drive systems on the market lack the performance advantage of a locking centre differential and rely solely on traction control to redistribute torque away from slipping wheels.
Exclusive to the WRX STI, the Multi-Mode VDC system offers the driver three settings: VDC Normal, Traction and Off. The Normal setting provides the highest level of system engagement, utilizing traction control (TCS) and VDC. The Traction setting is more performance-oriented, employing less-restrictive VDC and disengaging the engine torque-reduction control. The Off setting disengages the VDC and the traction control functions.
Also exclusive to the WRX STI, the Brembo Performance Brake System uses ventilated 4-wheel disc brakes with Super Sport anti-lock (ABS) and Electronic Brake-force Distribution (EBD). Front discs measure 326 mm (13.0 inches) in diameter and use 4-piston, fixed-position calipers; the 316 mm (12.6 inch) rear discs use 2-piston, fixed-position calipers. Taking input from a lateral g-sensor, a steering angle sensor, a yaw sensor and a brake pressure sensor, Super Sport ABS can control the braking forces at each rear wheel independently, which optimizes braking ability during hard cornering to help reduce understeer. In contrast, conventional ABS systems control the rear wheels as a pair, reducing the braking force to both rear wheels equally.
Sporty, Spacious and Versatile Interior
New for 2011, the WRX STI interior is finished in black and silver to highlight its sporty design. The colour of each metallic part was unified to dark metallic and sharp silver. Trim panels, steering wheel air bag cover and steering wheel switches are now dark titanium finish.
The standard tilt and telescopic steering wheel is a three-spoke, leather-wrapped design embossed with the STI logo in its centre. The wheel features control switches for Bluetooth(R) hands-free phone function. The WRX STI models are equipped with standard aluminum-alloy pedals and driver's footrest. Performance-design front seats integrate the backrest and head restraint into a single structure. The instrument panel's electroluminescent gauges use indicator needles that sweep the gauge faces upon engine startup.
The compact layout of the double-wishbone rear suspension helps to minimize intrusion into the cargo area, providing a wide and deep luggage compartment. In the 5-door models, the wide and flat load floor can accommodate two Tour-size golf bags with the rear seat backs in the upright position. In the 4-door sedan model, which is 165 mm (6.5 inches) longer than the 5-door, the extra space provides for a larger, deeper trunk that can accommodate three Tour-size golf bags. A 60/40-split folding rear seat further boosts cargo capacity and convenience, and the 4-door also features a rear seat fold-down centre armrest.
New for 2011, the standard audio system features an AM/FM stereo with single-disc CD player and six speakers; a 3.5 mm auxiliary input jack; Bluetooth hands-free calling; a MediaHub for iPod(R)/USB audio integration with Bluetooth(R) streaming audio and SIRIUS Satellite Radio capability. Steering wheel mounted controls for the audio system, cruise control and Bluetooth(R) are standard for all 2011 Impreza WRX STI models.
The WRX STI Sport-tech features a power sunroof, xenon High Intensity Discharge (HID) headlights, automatic climate control, mirror-integrated LED turn signals, a Pioneer(R) AVIC in-dash navigation/audio system (AM/FM/CD/MP3/WMA) with detachable touchscreen and Pioneer A-Series speakers.
Subaru Safety
Electronic Brake-force Distribution (EBD) provides precise control of braking pressure between the front and rear wheels based on the vehicle load to improve stability and stopping distances. Brake Assist analyzes the force and stroke on the brake pedal and increases hydraulic boost to provide enhanced emergency braking, also activating the ABS system early if needed.
All Impreza models utilize the proven advanced Subaru Ring-Shaped Reinforcement Frame body structure with front and rear crumple zones. Front seat side airbags and side-curtain airbags are standard on all Subaru models. The Subaru Advanced Frontal Airbag System (SRS) features a passenger side front seat sensor module that detects weight - first determining if the seat is occupied, and if so by a child or adult - to control airbag deployment. As part of the system, the dashboard features an airbag indicator light. There are 3-point seatbelts for all seating positions, including front height-adjustable seatbelts with electrically triggered pre-tensioners and force limiters.
