Thursday, December 27, 2007

Ford Mustang Shelby GT vs. 2008 Subaru Impreza WRX STI

By Josh Jacquot, Senior Road Test Editor Date

Look no further than the hood scoops on the 2008 Subaru Impreza WRX STI and 2007 Ford Shelby GT to find the fundamental difference in their personalities. It's here that both cars' sense of purpose and ability is displayed prominently and publicly as a statement of their true character.Integrated into the STI's hood is an elegant and somewhat menacing scoop that feeds air through the engine's intercooler.

It's a functional and defining detail on all boosted Subarus and it enhances the car's already purposeful demeanor.On the Shelby's hood lies a nonfunctional remnant of days gone by. Days when bias-ply tires were making the smoke. Days when performance was measured by the number of barrels in your carburetor. Days when cars were built with the delicate precision of dynamite. From the driver seat, we could see underneath the Mustang's hood scoop to the road ahead, a constant reminder that it's phony and just plain disappointing on a car that bears the name of such a legend.Same Price Tag, Different State of MindSo why compare two cars whose target customers are so different? Well, first of all, they cost the same.

The STI is slightly pricier at $39,440, only marginally more than the $39,180 Shelby. With as-tested prices within $300 of each other, the reality of cross-shopping these two on price alone isn't an arguable point.We'd argue that there's another common mission between the two: putting a smile on their owners' faces. Really, they're both about having fun.

Whether that fun means late-night powerslides in the Wal-Mart parking lot or Sunday morning pace-note sessions up your local canyon road, depends only on your state of mind.Plus, these two machines are remarkably similar in the power department. The STI's 2.5-liter turbocharged flat-4 is rated at 305 horsepower and 290 pound-feet of torque. The Shelby's 4.6-liter V8 is stronger than that, but not by much.

It generates 319 hp and 330 lb-ft of torque, slightly more than a standard Mustang thanks to a more efficient exhaust system, cold air intake and a revised engine calibration (which mandates premium fuel). A six-speed manual transmission puts the STI's power to all four wheels, while a five-speed manual drives the Shelby's rears.

Doughnuts and HorseplayPlant your right foot to the Shelby's floorboard and you're rewarded with an engine note so patriotic you'd swear Francis Scott Key tuned the car's dual exhaust. It's a deep, powerful sound that perfectly accompanies the thrust that comes with it. It'll take $800 in custom exhaust to get this much aural reward from the STI and even then it will only be pleasing if you happen to like the off-kilter thrum of a flat-4.

What's more, a dip of the clutch and jab at the throttle is a sure key to the best powerslides this side of a GT500.

The Shelby GT's balance on smooth surfaces is good and the information it offers a driver through its chassis is encouraging enough that we found ourselves with ample confidence to drive it very hard. Its steering is light but responsive and communicative enough to inspire reasonable confidence.

There are few rewards in life greater than executing a perfect, tire-smoking powerslide, gathering it up and pulling up confidently at the next signal. This happens often in the Shelby GT. It's the kind of fun you can't have in any Subaru. But like mullets and mopeds, it's a bit of a novelty.If outright speed is your jones, you should buy the STI. This latest version of Subaru's flagship is silly fast on any surface you choose.

It eats midcorner bumps like a turbodiesel wood chipper sucking down a sapling. It treats road irregularities, gravel and damp surfaces with the same indifference the Shelby does burnouts — they're all in a day's work.Very few cars sold today will match the STI's midcorner speed. Nor will they exercise its mind-bending grip on the tarmac with such relaxed confidence. Its electronically controlled center differential and front and rear mechanical limited-slip differentials twist any road into submission.

The staggering speed comes from perfectly managing this combination of long-travel suspension, substantial power and Velcro-like grip. Part of that management strategy includes the three-way SI-Drive throttle switch on the console that allows the driver to adjust throttle response between pointlessly slow and just right. There are also nine settings for the center differential — three auto and six manual — which is too many, but testifies to the amount of control a driver has in this car. Bottom line: There's not a Mustang made that will match it on any real road.Inside and OutUnless a few Shelby badges and a high-effort Hurst shifter are your idea of interior upgrades, you won't notice much difference between the office of a Shelby GT and a standard Mustang.

There are the same slick, flat seats, built-to-cost Ford switchgear and materials and presentation we've come to accept at the standard Mustang's $25,000 cost of entry. But this car adds a 55 percent premium, which isn't reflected in its interior.

The STI provides the expected bump in quality. From its Alcantara suede-and-leather-covered seats to its double stitching, to new plastics, there's a very different feel inside an STI than there is in a WRX.

Too bad its six-speed tranny isn't as quick-shifting or precise as we'd expect given its direct-shift configuration, and its seats are too wide to be as supportive as we'd like.

Still, they're better than the Mustang's wide, flat chairs.There's also an automatic climate control system where the Shelby has only fan speed, temperature and mode dials. Our STI was fitted with the optional navigation system, which more than compensates for the minimal price difference between the two.Outside, neither car will be mistaken for its lesser counterpart.

Most obvious are the STI's huge fenders. Bulging at every opportunity, the new shape has the same polarizing effect on Subaru enthusiasts as did the new WRX. We think the hatchback shape expands its appeal to buyers who might have previously overlooked it as too boy racerish. But love it or hate it, you're not going to overlook it.

The Shelby offers equally juiced-up exterior styling. In 2007 it was only available in black or white but will be produced in Vista Blue with the same silver stripes for the 2008 model year. There's a unique front fascia, lower airdam and side scoops plus the not-a-hood scoop. Eighteen-inch Torque Thrust look-alike wheels are at all four corners.

The wheels, scoops and stripes, however faux-retro, are striking in combination with the GT's black paint.Living Life 13 Seconds at a TimePredictably, the Shelby is 157 pounds heavier than the STI (3,508 vs. 3,351 pounds), which didn't help its case in our acceleration tests.

All-wheel grip and lots of grunt give the less powerful Subaru the ability to outrun the Shelby out of the hole — an advantage it holds all the way to the end of the quarter-mile. With an admittedly abusive launch, our STI hit 60 in 4.8 seconds — 0.4 second quicker than the Shelby.

Breaking the traps in 13.3 seconds, the Subaru's lead remains the same. Pulling hard, the Shelby gets there in 13.7 seconds, and has a 1.5-mph advantage in trap speed (103.9 mph vs.102.4 mph).If drag racing is your thing, the Mustang is your car. Slap on some drag radials and it'll likely run with the STI.

Plus, it feels a hell of a lot less likely to self-destruct during a day of redline launches. Subarus have always proven durable during our testing, but the physical load on the STI's drivetrain during a hard launch is unquestionably violent.Brakes are another area where the hardware and engineering advantage of the Japanese car is apparent. Stopping from 60 in only 106 feet, the STI is in a different league than the Shelby, which requires 126 feet.Look closely at the hardware and the Subaru's value and performance are clear.

The STI is fitted with 13.0-inch rotors and four-piston Brembo calipers up front, while the Mustang makes due with 11.5-inch rotors and two-piston calipers. Perhaps an even greater factor in our single-stop test are each car's tires. The lighter STI's 245/40R18 Dunlop SP Sport 600 summer tires are far stickier than the Shelby's 235/50ZR18 BFGoodrich g-Force KDWS all-season tires.Straightening the Curves, Flattening the HillsThose stickier tires also helped the STI embarrass the Shelby in the slalom.

At 72.0 mph this is the fastest Subaru we've ever tested. Despite its Ford Racing handling package, which is lower and more heavily damped than a stock Mustang, the Shelby only managed 68.0 mph — exactly the same speed as Ford's GT500. Unfortunately, the lower suspension lacks both travel and compliance, giving the GT a wagonlike ride.Around the skid pad, however, the Shelby was surprisingly close, circling at 0.88g vs. the STI's 0.90g. It once again demonstrated the always-engaging ability to drive in never-ending sideways circles with a white haze pouring off its rear tires.

Did we mention that this is fun? Or that it can't be done in a Subaru?More valuable than our instrumented handling data is each car's real-world behavior. It's here that the Subaru's abilities are dramatically greater than the Shelby's. Its ride is compliant but controlled — a near-perfect compromise.

In the real world where there are bumps, off-camber roads and gravel, there's simply no contest. On one winding California road we reached the Mustang's limits (and its bump stops) before the STI's driver even knew we were trying to keep up.The Easy WinnerUnpack the data and the driving impressions and the results are overwhelmingly clear.

In fact, out of the 46 categories scored in this test, the STI gave up only two to the Shelby: as-tested price and quarter-mile trap speed. It tied or won every single category in our 27-point evaluation, dominated when it came to feature content and was every editor's personal and recommended pick. That's kicking some major ass.Of course this doesn't tell the whole story. The Shelby will put a grin on your face as quickly as it will autograph the tarmac in your local Wal-Mart parking lot. This, while great fun, is of limited value, which is why the Subaru wins. It's quicker in virtually every test and unquestionably quicker over any road.

It rides and handles better and its interior is light-years ahead of the Shelby.The takeaway is simple. If you want a driver's car, one that's as capable in a straight line as it is on virtually any road, the STI is your car.

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