Subaru’s all-wheel-drive performance flagship finally moves onto the latest Impreza platform for the 2015 model year with substantial upgrades to body rigidity, suspension and steering. The tried and true 2.5-liter turbocharged boxer four-cylinder engine with 305 hp and 290 lb-ft of torque carries over to the new car, which may be a disappointment to some since it’s been employed under the hood of the STI from the beginning of its U.S. run. However, there were some ECU improvements for better throttle response. A six-speed manual remains the only transmission option.
Most will agree that the previous generation STI was soft, which Subaru did try to remedy during a midcycle model update for 2011 that saw the return of the sedan body and a thorough firming of the suspension. It helped, but the chassis still wasn’t up to snuff to make the best use of the STI’s drivetrain, while the migration to the new platform does. The structure boasts more high-strength steel which is further backed up by uprated springs, dampers, cross members and suspension bushings. The result is a front suspension with lateral stiffness that’s up by 14 percent, and a rear suspension that’s improved by 38 percent compared to the outgoing STI.
Sharpening things more is a quicker 13.0:1 steering ratio for the hydraulic power steering system versus the 15.0:1 ratio in the old car and the new WRX’s 14.5:1 ratio. Delivering the stopping muscle are four-piston Brembo brakes in front and two-piston Brembos out back, with the system benefiting from a larger master cylinder and upgraded brake booster. The package rides on 18-inch wheels wrapped with Dunlop Sport Maxx RT performance tires.
Besides the engine, there’s a lot of other familiar equipment, including the adjustable SI-Drive powertrain system, the multimode controlled center differential, helical front limited-slip differential and Torsen rear limited-slip diff. But the multimode dynamic and stability control system adds active torque vectoring that applies the brakes to the inside front wheel in turns to provide more neutral cornering performance.
From the outside, it’s unmistakably an STI with the signature large functional wing out back, and wide body treatments on the fenders, doors, rear quarter panels, bumpers, rear diffuser and hood scoop. Head- and taillights are now LED and the hood is now made from aluminum to help save weight.
The cabin is more practical, thanks to the 1-inch larger wheelbase that helps contribute almost 2 additional inches of rear seat legroom. Larger door openings make getting in and out of the STI easier and there’s better visibility out of the car with skinnier A-pillars and a lower dash. Specific to the STI are well-bolstered front seats with Alcantara inserts with red and black leather bolsters, a thick flat-bottom leather-wrapped steering wheel with audio and Bluetooth controls, a 3.5-inch LCD center gauge cluster for vehicle warnings such as low oil alerts and current gear selection. Other features include a 4.3-inch LCD central dash screen to display rear camera images, boost gauge, audio information and outside temperature. Dual-zone automatic climate controls, HD radio, Bluetooth phone and music streaming and satellite radio are also standard.
For STI shoppers looking for a little more luxury, a Limited model is once again offered, with a leather-trimmed interior, eight-way power driver’s seat, Harmon/Kardon sound system, and a moonroof.
To celebrate the debut of a new STI model, Subaru will offer a limited production STI Launch Edition that harks back to the Subaru rally cars that have claimed three World Rally Championships. Only 1,000 will be offered, all painted WR blue, rolling on forged gold BBS wheels, featuring blue interior trim and a STI short-throw shifter.
How does it drive?
It doesn’t take much time behind the wheel to pick up the behavior differences of the new car. During the first turn of the steering wheel, you’ll notice the quicker response to inputs, along with a satisfying heft tuned into the hydraulic system. Jump onto the throttle hard, and the engine exhibits right-now response to make rev-matching for downshifts a cinch. The brakes bite down hard from top of the pedal.
All of this is great down a tight, winding two-lane road with numerous blind corners requiring you to jam on the brakes hard because you’re unsure of what exactly is around the next turn. Through longer sweepers, the STI grips nicely with little lean, while the ride quality is stiff but certainly manageable for daily driving. The cabin is also much better isolated from road and wind noise.
The performance improvements really shined around Mazda Raceway Laguna Seca, where we got a handful of hot laps around the historic road course. With SI-Drive in sport sharp mode and the center differential set to Auto - for a torque bias to the rear more often the STI feels neutral around the track with high-grip limits. Understeering tendencies are greatly reduced now, and the car is easy to place where you want it on track. Again, the car feels tied down, with the body motions remaining well-controlled around the challenging and quick road course.
It felt like we were making full use of the 305 hp from the carryover powertrain, which wasn’t the case in the previous car on track. We can comfortably say that the new STI has become quite the track car.
Brakes were strong for the majority of our time at Laguna Seca, with them easily scrubbing off speed as we shot up towards the corkscrew and diving into turn two, but the pedal did eventually get a little squishy feeling during our last session on track.
Do I want it?
If you’re a Subaru fan, it’s a no-brainer: You’ll definitely want to get your mitts on a 2015 Subaru WRX STI. Subie fan boys could get past the fact that older STIs were flying tin cans with interiors that were pieced together with hard plastic panels that creaked like an old, warped hardwood floor and were light on features. As long as it packed a potent turbo boxer engine, all-wheel drive and a giant wing out back, it was fine. What problems they did have with the car could easily be addressed in the aftermarket where upgraded parts are plentiful.
For those who don’t have a strong pre-existing affinity for Subaru vehicles and the Subaru performance lifestyle, it was difficult to get past the old economy interior and general crudeness of a machine that costs $35K. The new STI takes huge strides in the cabin, with an abundance of soft-touch surfaces throughout; overall, it feels like a more substantial and better-put-together piece. Its performance is unquestionable and is almost track-ready straight out of the box with the chassis and suspension updates. Slap some high-performance brake pads on, and make sure to get some high-temperature brake fluid into the system, and you’ll be ready to go.
If you just want an extremely quick daily driver and don’t plan on any track-day escapades, then the 2015 STI is better suited for that, too, with the interior quality improvements, and roomier backseat and trunk. Yes, the ride is firm on road, but there’s still enough damping tuned into the suspension to smooth out smaller bumps.
2015 Subaru WRX STI
On Sale: March
Base Price: $35,290
Drivetrain: 2.5-liter, 305-hp, 290 lb-ft turbocharged H4; AWD, six-speed manual
Curb Weight: 3,386 lb
0-60 mph: 5.1 sec (mfr)
EPA Fuel Economy (City/Hwy/Combined): 17/23/19 mpg (mfr est)
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