The Good: The all-wheel-drive system and the limited slip differentials give the 2008 Subaru Impreza WRX STI excellent grip. Above 4,000rpm, its engine rockets the car forward, and we like its available navigation system. The Bad: We were less than impressed by the audio quality of the STI's stock stereo. Its very uneven power delivery makes everyday driving and low power maneuvers difficult. The Bottom Line: The 2008 Subaru Impreza WRX STI is a blast on the right kinds of roads, but gets tiresome on the daily commute. Music fans will be disappointed with the stereo. Photo gallery:2008 Subaru Impreza WRX STI Last year we tested the 2008 Subaru WRX and were left hoping the STI version would make up for the suburbanization of the model. Well, the 2008 Subaru Impreza WRX STI arrived in our garage and set all our worries to rest. From our first look at the STI parked in our garage, we could tell that it was a pit bull compared with the cocker spaniel-like standard WRX. The smooth sides of the standard WRX get bulked out by meaty fenders on the STI, wide enough to make room for the 245\/40R18 Dunlop Sport 600 summer tires wrapped around 18 inch rims. Big Brembro brakes sit in the rims, and special vents sit behind the front fenders ready to bleed off excess heat. Where the standard WRX we tested was the sedan, the WRX STI only comes as a hatchback--an unnecessarily bulky body for a car that should not be consigned to grocery runs. The blister-like design of the new WRX looks even worse in the hatchback STI, with its weirdly rounded back end. We weren't at all impressed with the stock stereo in our STI, but the car can be optioned up with a navigation head unit that includes Bluetooth cell phone integration and an additional 20 watts for the audio system. Test the tech: WRX compared When we reviewed the standard WRX, we complained about the body roll in hard cornering. To tech test the STI, we took it over the same winding mountain road we had driven with the WRX to see if the handling and overall performance was different. Right from the start, we can attest to a major improvement, as the STI gripped the road and stayed flat in the hardest turns we could throw its way. The STI gets big vents behind the front fenders, something not seen on the standard WRX.The road we took runs from the California coast, near Stinson Beach, inland toward San Rafael, North of San Francisco. The first half of this road is about a lane and a half wide in total, without center markings, and running through ravines and along hillsides, with a number of rising hairpin turns. The second half broadens out to two marked lanes and has generally broader turns, although there are still a few sharp hairpins. The STI has Subaru's SI drive feature, which lets you set the throttle response among three positions: Intelligent, Sport, and Sport Sharp. We left it in Sport Sharp for this run, getting the quickest response from the engine. The car also has, along with limited slip differentials on the front and rear axles, an adjustable center limited slip differential. For most of the run, we left the center differential in automatic mode, although we tried its minimal and maximum lock positions as well. One of the first things we noticed about the STI was its almost complete lack of power at low rpms. We approached our first hairpin turn in second gear, hitting the brakes as we prepared to snap the wheel around. As we hit the gas on the entrance to the turn, the car bucked and bogged down because of the slow engine speed, barely reacting to our insistent push on the gas pedal. It was with disappointing speed that we came out the other side. The car has amazing boost between 4,000rpm and 6,000rpm where it gets its peak 305 horsepower. However, it completely bogs down about 2,000rpm. Unfortunately, with this tight of a turn, we had no choice but to let the engine drop its speed. On a similar hairpin, we tried dropping it down to first gear, which gave us decent boost out of the turn, but it forced us to practically park on the approach. Our test road has a few 10 mph hairpin turns, challenging to any car. On the broader turns where we could make our attack at 30 mph or 40 mph, the STI handled extremely well while requiring us to put in a satisfying amount of work with the wheel. The car has visceral handling, forcing us to use the wheel throughout the corner. While some people prefer a car that will take corners effortlessly, the STI is for people that like to be heavily involved with the driving experience. We had a great time blasting through the apex of a turn, feeling through the seat of our pants for wheel slip, modulating the accelerator while working the wheel to keep the car on course. As for wheel slip, we didn't feel much of that, as the STI is incredibly grounded. We could feel the wheels biting into the road as the car transferred torque appropriately, keeping the front end from running towards the outside of a turn. One particular section had a slight curve marred by a series of humps in the road. It's the kind of thing that will bounce many cars' tires clear of the asphalt, but the STI rode over those humps like a snake, its stiff suspension keeping the tires in contact with the road at all points. During our drive, we tried locking and loosening the center differential, but couldn't feel much of a difference. The center differential's maximum lock is for slippery conditions, such as mud and slush, while the looser setting is supposed to work in dry conditions. For our purposes, the automatic setting did the trick. The standard WRX gained a few points over the STI model because of its more even power delivery--its peak horsepower comes at 4,800rpm so it wouldn't leave us in the lurch on the approach to a hairpin. However, we preferred the STI overall for its markedly better handling. As a bonus, the STI gets a six speed manual transmission, which we like better than the five-speed manual in the standard WRX. The gears that count, second and third, seem to have similar ratios, but sixth is a nice gas saver when you're driving at freeway speeds. In the cabin It may seem unnecessary to talk about cabin tech with a rally car such as the 2008 Subaru Impreza WRX STI, but we like good music as we race over mountain roads. Also, navigation systems can help you get to those good roads, as well as alert you to the length and sharpness of that next turn in the road. Our STI came with the stock stereo, an underpowered system with the bare essentials of modern technology. The stock stereo in the STI doesn't have much power.The stock stereo can be optioned with either XM or Sirius satellite radio, although we haven't been too impressed with the integration of this feature in other Subaru models we've seen. It also comes standard with a six-disc in-dash changer that can read MP3 CDs. There are dedicated buttons for moving through folders, which is nice, but the display only shows file and folder names, not ID3 tags for album, artist, or song title. The audio system uses an impressive 10 speakers, and we liked the bass the system produced. On tracks with heavy bass lines, we could feel the doors of the car shaking, but we also noticed some speaker hum. The highs and mids weren't very distinct, and the system ultimately didn't have much power. Subaru claims an 80 watt amp, but we were able to turn up the stereo to its arbitrary maximum volume of 40 without being deafened. We are a little baffled that the navigation system can only be ordered with either the silver or the gold BBS wheels. We don't know what the navigation system has to do with the wheels, but it means a higher option price for Subaru of $3,800, where navigation alone would probably run about $2,000. We used the navigation system in the standard WRX, and evaluated it in our review of that model. It is an excellent and thoroughly modern navigation system with nice map resolution and a full POI database. Further, Bluetooth cell phone integration comes with the navigation system, but we haven't had a chance to evaluate it. The stereo wattage is also increased to 100 watts--it's still not that powerful, but it's an improvement. Under the hood The real story behind the 2008 Subaru Impreza WRX STI is in the powertrain, a 2.5-liter boxer four-cylinder engine blown to 305 horsepower with a turbo and intercooler. As we mentioned, the 305 horsepower comes at 6,000rpm, right near redline, and its 290 foot pounds of torque comes in at 4,000rpm. In all sorts of driving conditions, from traffic to the mountains, the car bucks and lags at low engine speeds, but above 4,000rpm it bolts forward with an amazing amount of boost. We tried out the different throttle response settings with the SI drive, ultimately deciding never to use the Intelligent mode, as it just make the car lag even more from start. Sport is good for every day driving, while Sport Sharp is fun on the twisty roads. Subaru squeezes 305 horsepower out of its four-cylinder engine with a turbocharger.The clutch and six-speed manual transmission have a very solid feel, and we were impressed to find that the car has a hill-hold feature. While stopped and facing the sky on a steep San Francisco hill, we put the clutch in, shifted to first, took our foot off the brake, and the car didn't roll back. We described the grip and handling in some detail above. We can't say the car has excellent composure in the corners, but it lets you play so much that we liked it. Subaru's all-wheel-drive system and the car's very stiff suspension work together to keep the tires locked to the road. The adjustable center differential is an interesting feature, but only seems useful if you actually rally this car. We can't imagine being out for a Sunday drive and thinking we need to set the center differential to two ticks below full lock. Fortunately, the automatic setting can be biased toward more or less lock. With the center differential in automatic mode, you push up or down the adjustment switch and the green Auto light on the speedometer displays a plus or minus next to it. You can bias the automatic setting of the center differential toward more or less lock.The STI isn't a car for those who want to maximize fuel economy, but we will spell out its mileage here anyway. The EPA gives the car a rating of 17 mpg city and 23 mpg highway. We drove the car hard while we had it, but still got an average of 17.4 mpg that, though not good, is better than we expected. The car doesn't stand out for emissions. It earns the minimum LEV II rating from California's Air Resources Board. In sum The 2008 Subaru Impreza WRX STI is a little pricey with a base of $34,995, no longer the bargain basement racer of yore. Our only options were a $75 cargo tray and a $163 center armrest. The BBS wheels and navigation package would have run us up another $3,800, bringing the total close to $40,000. As it was, the $645 destination charge brought our total up to $35,878. For our rating, we generally give the car high marks. We aren't fans of the design aesthetics, so it takes a hit there, but as a hatchback, it does have a practical nature. For performance, we give it nearly a top rating, with the only faults being the very uneven power delivery and the mediocre fuel economy. For cabin tech, we're giving it a relatively high score because of the available navigation system, which we liked in the standard WRX. However, it also gets docked points for the stock audio system.