Like its predecessor, the fourth-generation Subaru WRX STI is powered by a turbocharged 2.5-litre four-cylinder 'boxer' petrol engine, maintaining a half-litre advantage over the regular WRX. Producing 227kW at 6000rpm and 392Nm at 4000rpm, power rises 6kW but torque falls 15Nm compared with the outgoing model’s motor.
Subaru hasn’t made performance claims for its all-new sports sedan, though the all-new WRX STI will almost certainly better the third-gen’s 4.9-second 0-100km/h benchmark.
The engine is paired exclusively with a six-speed manual transmission (the auto option has been dropped), which includes an STI short-throw shifter in the special WRX STI Launch Edition specification, which will be limited to 1000 units and will also feature WR Blue paint, gold BBS forged alloy wheels and unique interior trim.
The 2014 Subaru WRX STI’s body structure features a higher percentage of high-tensile steel than before and special stiffening elements at key locations – the stiffer chassis claimed to help yield a “super quick” steering response that was benchmarked against top-handling sports cars.
The 13.0:1 steering ratio provides a 2.5 turns lock-to-lock compared with 14.5:1 and 2.8 turns for the regular WRX.
Like previous STI models, the new generation uses an exclusive inverted-strut front suspension system that promises higher levels of cornering agility, along with aluminium front lower L-arms that reduce unsprung vehicle mass.
The STI-tuned suspension works in tandem with 18-inch alloy wheels shod with 245/40-aspect performance tyres.
The WRX STI’s Subaru Intelligent Drive (SI-Drive) powertrain management system allows the driver to customise the vehicle’s driving characteristics by selecting between three modes – Intelligent, Sport, and Sport Sharp – via a rotary dial on the centre console. SI-Drive regulates the engine control module and fine-tunes the electronic throttle control system to deliver the desired effect.
Exclusive to the Subaru WRX STI is its multi-mode driver-controlled centre differential version of the brand’s famous symmetrical all-wheel-drive system, with a mechanical limited-slip centre differential augmenting an electronically controlled centre differential in the pursuit of enhanced torque transfer performance.
Subaru says a helical-type limited-slip front differential and a Torsen torque-sensing limited-slip rear differential optimise side-to-side distribution. The AWD system features three automatic modes with varying degrees of centre diff locking, while in manual mode the driver can select one of six centre diff locking levels to suit the conditions.
Active torque vectoring – an advancement of the car’s electronic stability and traction control system – applies braking to the inside front wheel for more neutral cornering. Drivers can select from three settings: Normal, Traction, and Off.
At 4595mm long, 1795mm wide, 1475mm tall and riding on a 2650mm wheelbase, the new Subaru WRX STI sedan is 15mm longer and 5mm taller than its predecessor, and measures 25mm longer between the wheels.
Subaru says rear legroom is up by about 50mm while boot space increases 20 litres to 340L.
A new flat-bottomed leather-wrapped steering wheel sits in front of a red-lit instrument cluster with a 3.5-inch LCD display.
A larger 4.3-inch screen sits at the top of the dashboard, integrating the WRX STI’s audio, climate, boost gauge, traction control operation, and rear-view camera displays. An optional 6.1-inch touchscreen adds satellite navigation and voice control.
Dual-zone climate control and a six-speaker audio system with Bluetooth phone connectivity and audio streaming also come standard, while in the US, the high-grade Limited spec adds leather upholstery, eight-way power driver’s seat, Harman Kardon premium audio system and a moonroof.
The all-new Subaru WRX STI is set to launch in Australia in April, a little over one month after the introduction of the new WRX, with pricing expected to compare closely with the outgoing model’s $54,990 starting price.
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