This WRX continues Subaru's tradition of horizontally opposed engines, meaning the cylinders are laid flat with the pistons on each side moving in opposite directions (same as the engines in Porsche's sports cars). Like all engine designs, this one has advantages and disadvantages. One of the advantages is compact size, and the prospect of installing the engine low in the car. Flat-four engines have a distinctive, loping vibration pattern that can quickly be distinguished by motorheads, though like all the vibrations in the new WRX, it's more muted than ever.
At face value, the engines don't seem to have changed much. Output in the standard 2008 WRX 2.5-liter four (226 horsepower, 224 pound-feet of torque) is identical to that of the previous model. Horsepower with the STi increases by 12 to 305 hp, with 290 lb-ft of torque. In both cases, it's a lot of power for the engine's size, yet the figures don't say much about improvements to the WRX engines. Both versions are now 50 pounds lighter than before (other things equal, that means better gas mileage), and fitted with the latest-generation control electronics to improve overall efficiency and reduce emissions. Perhaps more significantly, the power curve has been broadened, so the power is available sooner on the rpm scale, and over a wider range. The acceleration-producing grunt comes sooner, and stays strong as the engine continues to rev.
The same sort of transparent refinement has been applied throughout the WRX's mechanical and electronic systems. For the first time, a single management program controls the electronic throttle, the full-time all-wheel-drive, and the Vehicle Dynamics Control. Even the antilock brakes are integrated. That allows a host of possibilities that can enhance safety and improve handling and overall performance.
The standard WRX takes care of just about everything for the driver, leaving the choices to the computer chip. The STi, on the other hand, lets the driver sort through a bunch of options using a series of buttons on the center console.
One STi feature, called SI-Drive, allows a choice of three maps for the electronic throttle, ranging from commute grade to extra aggressive. This allows the driver to control how much the engine accelerates with a given movement of the gas pedal: smooth, mild response to big dips on the pedal, or major acceleration with small dips. The VDC also offers choices: Standard, Off, and Performance, which allows enough wheel slip to slide the car but still tries to gather things up if it gets too sloppy. A manual adjustment for the center differential controls how much of the power is sent to the front or rear wheels, as it is in a real World Rally Championship car. Between the various throttle maps, stability and differential settings, there are almost enough permutations to confuse a race-car engineer.
The leave-it-to-the-computer settings in the standard WRX will be fine for the majority of drivers, but we suppose those paying an extra $10,000 for the STi might expect some tangible features to impress their friends. In the right conditions, driving enthusiasts will have fun playing with the various settings, and those stressed out or confused by the adjustments can go with the default, automatic settings in the STi.
There's not much confusion when you step on the gas, even in the standard WRX. This compact just goes, noticeably more quickly than the vast majority of cars in its size or price range, with a swoosh from the turbocharged engine that makes a viscerally satisfying experience. Yet power delivery in the 2008 is more linear than ever, so you don't have to get the engine screaming at 6000 rpm to feel the pull. The WRX will jump as readily if the engine is humming at 2500 rpm when the driver steps on it.
The weak link in this gas-and-go process might be the gear-change for the five-speed manual transmission. The shifter has nice weight and resistance, with reasonably short transfer between gears slots, but the movement is a tad more stretchy than we might like in true high-performance car. Nonetheless, the driver adjusts quickly, and working the gears in the WRX is a very pleasant experience. Starts are aided by Subaru's Hill-Holder feature, which keeps the car from rolling backward as the operator releases the clutch pedal on an incline.
The optional automatic transmission works fairly well, with nice, smooth upshifts and reasonably quick downshifts when you step on the gas to pass. Buyers who need an automatic should be happy, but we're reluctant to recommend it nonetheless. As five-, six- and even seven-speed automatics proliferate in the car industry, the WRX's four-speed seems dated, particularly in a car that's technologically advanced in other respects. Still, our reluctance has less to do with how the WRX automatic works and more with the fun a driver misses by forgoing the manual. The STi leaves no such option, because it's available only with a six-speed manual.
The STi really quick: Ford MustangGT and Aston Martin V8 Vantage quick, or 0-60 mph in about five seconds flat, with an engine about half the size. Yet even more than in the standard WRX, the STi's new level of refinement is apparent. The power comes smoothly and more evenly than before, even with the electronic throttle management set in its most aggressive mode. And again, there is less commotion or mechanical fury apparent to the driver as the STi hurtles toward the horizon; just the rich exhaust rumble of a well-tuned, high-performance engine.
The STi's new found civility is apparent in all its dynamic characteristics. Its suspension tuning, or the mix of overall ride comfort, sharp handling and pavement-sticking grip, is one of the highlights. Steering in both the standard WRX and STi is lighter than we'd expect in most performance-tuned cars. But it's also fairly quick, so the car turns a lot with small movements on the wheel, and accurate. With a little familiarity, the typical driver will have no trouble directing these cars in very precise fashion.
Is the ride soft? Not exactly, but it's softer than before, and it's missing the cruder, teeth-chattering shocks of the original STi. We'll call the suspension movement controlled compliance, with enough give to be comfortable on all but the Midwest's worst roads, much like the typical European sport sedan. The STi's suspension dampens body lean and fore-aft bobbing firmly (still more firmly than the standard WRX, but less firmly than the previous STi). Yet it allows the car to settle smoothly after big bumps, protecting those inside from big jolts or repeating, annoying up-down motions. And it still offers the driver everything he or she needs to evaluate what's happening under the seat, or to build confidence in the car's behavior.
Confidence in a car is a good thing at a race track, and we suspect a lot STi buyers will try their cars at a track day with the local owners club. We had a chance to sample the 2008 STi at Northern California's fast, deceptively simple Laguna Seca road course, where some of the world's best drivers have made some very famous mistakes. There, the STi demonstrated potential street driving rarely reveals, except perhaps in emergency situations where a car's capability can be the difference between a deep sigh of relief and disaster.
This new, more refined STi might merit the label unflappable, and it might be the perfect car for a beginner's introduction to a race track. At the track, the quality of its brakes and stability control electronics might be the difference between embarrassment and disaster, as when a beginner crests a hill and realizes the entrance to the next corner isn't where he or she thought it was.
At its handling limits, the STi has a slight inclination to understeer, or to generate the feeling that its front wheels are pushing off the road. Yet that tendency is less than in the typical front-drive car, and the STi's all-wheel-drive system allows the driver to get the front end to tuck into a curve by adding a little more gas. With the electronics doing the job they're designed to do, the STi stays planted under rough, abrupt or heavy-handed inputs on its controls. Whether braking hard into a curve, or panic-braking with a sudden twist of the steering to avoid an accident, the electronics are always working to keep the car's weight balanced and the tires on that fine line between maximum grip and skid. The STi helps take care of the beginner without strangling the joy out for skilled drivers, and it allows exceptionally skilled drivers to turn all the electronic aids off.
The brakes on these cars are outstanding. On both the WRX and STi, the rotors are larger than those on the typical small car, but especially so on the STi. Its brake hardware is supplied by Brembo, which also makes the brakes for Ferrari and other ultra-high performance car builders. Meanwhile, the ABS on these cars is among the most sophisticated available. It uses various sensors to control the braking force at each rear wheel independently, which in turn can help keep the car's rear end from sliding around while braking aggressively in a curve. Next Page