Selasa, 20 Juli 2010

Subaru Impreza WRX STI sedan

Perhaps it is unfair to consign the last-generation Subaru Impreza WRX STI to a place in history best occupied by the likes of New Coke and the Pet Rock. Yet when Subaru unveiled the 2008 STI--the replacement for its legendary, flame-snorting predecessor which launched in the United States in 2004--there was no escaping the feeling that its performance flagship might have lost as much as it gained along the way. And for what?

Yes, the 2008 STI was smoother and quieter. It also felt softer and easier to drive, even--and this was the depressing part--tame in comparison with the original. Some of that feeling was simply perception born from inevitable refinement, but it remained in place to some degree even as Subaru's engineers improved the car's suspension and engine for 2009, with even more suspension upgrades added to last year's STI Special Edition. Unfortunately for the product planners and the early adopters, this is often the case when an inspiring machine evolves, especially one that arrived on the scene providing a driving experience so genuine that it earned a diverse loyalist following spanning traditional gearheads, rally nuts and the sterotypical street-racer fan boys trained on PlayStation more than their local road courses.

Two and a half years later, Subaru does not feel a need to apologize for the last STI, as sales have remained relatively stable at around 3,000 to 3,500 cars sold per year. It does, however, acknowledge “a difference in [company] philosophy when that car was launched,” as one spokesman said on the eve of the 2011 model's introduction. “You can't please everybody.”

No, but first drives of the new WRX and WRX STI indicate that Subaru has come much closer to doing so this time around.

The most obvious distinction is the return of a sedan, which joins the five-door hatchback in the STI lineup. Subaru has always offered a four-door version of the WRX but binned the STI sedan for 2008 because it wanted to sell potential buyers on a direct link between the road car and the hatchback-based World Rally Championship contender of the time. Still, while the five-door's shorter overhangs made it easier for WRC driver Petter Solberg to know where his rally car's corners were, and therefore keep it in one piece at speed through the forests of Wales and the snow banks of Finland, the design failed to resonate with a fair portion of hard-core customers.

“Consumer feedback [said] that a lot of people didn't like the hatch; a lot wanted the sedan,” Subaru's spokesman said. “When we took that away, [some thought the car was] too mild, too mellow.”

There is far less chance of that now, even if you still feel that the latest design lacks the original's raw visual impact and apparent singularity of purpose. The WRX and STI sedans and hatches now share aggressive, wide-body panels. The appearance is all new to Impreza sedans, while revised lightly in the front on five-door versions. To distinguish the STI as the top-of-the-line edition, the sedan once again flaunts a tall signature rear wing, now noticeably convex in sculpting, and all STIs receive bigger wheels and tires and, of course, STI badging.

If you were hoping for increased power, you'll want to skip the following section, as engines and transmissions remain unchanged. The WRX's 2.5-liter turbocharged boxer four still features maximum boost pressure of 14.2 psi and produces 265 hp at 6,000 rpm and 244 lb-ft of torque at 4,000. The STI engine, with 14.7 psi of boost, remains rated at 305 hp at 6,000 rpm and 290-lb-ft at 4,000. Subaru engineers say that the WRX still runs from 0 to 60 mph in 5.4 seconds, the STI in 4.9. Experience shows that Subaru's official acceleration numbers tend to fall into the conservative zone, though; as with the old cars, you should be able to shave 0.2 to 0.3 second from those times. Officially, the WRX tops out at 142 mph, while the STI sedan's improved aerodynamics bump its top speed to 158 mph, 3 mph faster than the hatchback.

Straightline running, though, is not what will make this generation of cars memorable or significant to the lineage, as they feel identical to their predecessors when you crack the throttle in pursuit of pure velocity. And as nice as the wide-body design and mildly reworked interior are (there's a new audio system and instrument cluster, and STIs are now available with leather seats and power moonroof in Limited trim), that's not enough to earn them a new chapter in the Book of Impreza. But what lies underneath just might, as it positively improves the handling with seemingly no reduction in ride quality.

According to Hiroshi Mori, the cars' general manager, “all [mechanical] changes for 2011 [are intended] to improve driver confidence, handling and response.” Initial impressions from a day behind the wheel of the WRX and STI say that he and his team achieved their target.

The key modifications lie within the suspension, which features a wider track (by 1.3 inches in front, 1.5 rear) made possible by the flared bodywork. WRX wheel and tire sizes increase as well, with 17- x 8-inch wheels versus the previous edition's 17 x 7. Tires measure 235/45, up from 225/45. As for the STI, wheel size carries over (18 x 8.5), as does tire size (245/40). The WRX also receives firmer rear suspension subframe bushings, and our brief drive on Colorado mountain roads indicates that there is less body roll through corners to go along with more grip.

Extended time in the STI, though, reveals the real performance story. Mori's engineers fitted the front suspension with a feature well known to racers and aftermarket performance-part junkies. “Pillow ball” bushings—or spherical bearings, if you prefer—attach the aluminum lower control arms to the front suspension's subframe. Whereas the old STI used economical rubber bushings with steel sleeves, the new design's proper steel bearings provide twice as much resistance to fore/aft forces and improve camber and toe stiffness.

From there, it's a trickle-down effect throughout the suspension. Front spring rate increases by 15.6 percent, the rear by an impressive 53 percent over the standard 2010 STI and 18 percent versus the aforementioned STI Special Edition. Antiroll bars are slightly larger (21 millimeters versus 20 in front, 19 versus 18 out back), and the ride height drops by 5 millimeters. Mori says that the STI now generates 0.93 g of maximum lateral grip compared with the 2010's 0.90, and there is 33 percent less body roll. The collective changes and newfound rigidity make better use of the front tires, which previously suffered high wear on the outer third of their tread.

Your backside relays the message better than any numbers on a chart ever could. Our drive on the road indicated improvements in grip, dive, roll and corner turn-in, with the STI taking a quicker, firmer and more confidence-inspiring attitude through corners that will be apparent to drivers of varying skill levels—just as Mori said.

Back-to-back drives in 2010 and 2011 STIs on Aspen Motorsports Park's twisting layout confirmed those feelings. While the 2010 car's tires roared in tortured pain, the 2011's rubber only chirped, even during deliberate attempts to push harder and harder in order to unsettle the chassis, to find the spot when an inherent “softness” emerged as it did in the old car. Such a scenario never happened. Front-end bite is much better, with less understeer and improved grip through all phases of cornering. The new STI appears to handle lateral transitions significantly better than the old, and without doubt, the difference between the two generations was indisputably laid bare.

As this was a first drive, plenty remains to be discovered about the latest WRX and STI. There are many more miles to cover in the real world before we have a definitive sense of whether Subaru has taken a major step toward rediscovering the line's old magic. But if initial impressions prove correct, there's only one thing to say about the previous incarnation.

It's history.

2011 Subaru Impreza WRX

On Sale: Late August/early September

Base Price: $26,220

Drivetrain: 2.5-liter, turbocharged, 265-hp, 244-lb-ft H4; AWD, five-speed manual

Curb Weight: 3,208 lb

0-60 MPH: 5.4 sec (mfr)

Fuel Economy (EPA): 21 mpg

2011 Subaru Impreza WRX STI

On Sale: Late August/early September

Base Price: $34,720

Drivetrain: 2.5-liter, turbocharged, 305-hp, 290-lb-ft H4; AWD, six-speed manual

Curb Weight: 3,384 lb

0-60 MPH: 4.9 sec (mfr)

Fuel Economy (EPA): 19 mpg

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