Road Test: Subaru Impreza WRX STI

Review by Feann Torr - 27/June/2008

The Subaru Impreza WRX STI is known throughout the motoring universe as a road warrior.

It's the Wesley Snipes of the car world: a short, sometimes misunderstood and very angry individual that packs a deadly punch.

Like it's arch nemesis the Mitsubishi Evolution, this small 4WD sports car takes turbocharging to the extreme, and in the process delivers massive acceleration from a relatively modest engine size.

The term 'giant-killer' is often bandied about, but has never been more apt than for a vehicle such as this.

But as has been the case with the new generation Subaru Impreza, which boasts a more European design aimed at wider range of buyers than in previous years, the question must be asked: has the STI lost its take-no-prisoners, punch-in-the-face attitude?

We were very keen to find out, so enough of the introduction and let's get into it:

Drive: 4.25/5

The first entry in my notebook after driving the Subaru WRX STI Spec R was "quick as".

While the Impreza WRX may have lost a bit of its bite, I can report that the STI is still one of most ferocious 4-cylinder vehicles ever made.

When the turbocharger is fully spooled at about 4000rpm under full throttle, the resultant surge of acceleration is strong enough to speed up digestion.

Indeed, the Subaru Impreza WRX STI is one of the world's pre-eminent blast masters, able to surge forward with remarkable potency and power from a standing start.

How many AWD cars are there that can get sideways or frequently break traction due to pure and unadulterated torque slamming through the driveline and exploding onto the asphalt through the wheels?

Apart from the Lamborghini Gallardo and Mitsubishi Evolution and this Japanese road warrior, not many I would wager.

One of first things I noticed after driving the car for a few hours was the heavy-duty feel it imparts; it feels mechanically tough.

You can feel the tight friction of the rally-bred all-wheel drive system as you roll to a standstill, indicating that this is no ordinary AWD. You can feel the rigid drive shaft and helical differentials though the gear shifter and clutch, and most of all you can feel the robust engine go completely berserk, time and again, whenever you stab the throttle.

While the 2008 Subaru WRX STI is not quite as unforgivingly rigid than its precursors, with a touch more give in the suspension, it still exhibits a very firm ride. Cat-eyes should be avoided.

So even though the STI isn't as stiffly sprung as before, this doesn't seem to have affected its cornering control. In fact, with a bit more give in the suspension it actually felt more controllable near its limit on public roads. 

On the racetrack this subtle suspension change may not be quite as welcome, but we didn't get to test it on the racetrack so we can't comment.

The banzai Subaru is a little more usable in everyday situations than its predecessors thanks to the slightly better ride quality, not to mention the engine's more accessible mid-range, but commuting and highway driving are secondary considerations when purchasing a car like this.

What it does best, and what it was built for, is attacking corners.

In this respect the 1505kg Subaru Impreza WRX STI is a triumph of automotive engineering. The level of grip it musters from its 245/40 R18 Dunlop SP 600 tyres is fantastic, and the way it holds its line though curves and bites into the road when accelerating is phenomenal.

The engine is positioned 22mm lower in the engine bay compared to the previous WRX STI and the front suspension is also a tad lighter, and this goes a long way to improving the way the angry little Subaru tips into corners.

Point to point it is an efficient vehicle, able to change direction without wallowing and capable of accelerating and then charging forward with incredible intensity and vehemence.

It feels far more decisive than the Subaru WRX too, and with increased body rigidity, "stiffened at strategic points to aid rigidity and performance" says Subaru, it's not surprising.

The steering is very direct, so you don't need to turn the wheel much to get the vehicle to change direction, and this only adds to the Subaru's feeling of agility.

The sense you get you when firing through corner after corner at nine tenths in the WRX STI is one of incredulity. How can I be hammering through such tight corners at these velocities?!

Then you just shift down a gear, and attack the next corner with even more ambition and the STI never misses a beat.

Full throttle, full brakes, then full throttle again and again: the car doesn't care. In fact it seems to perform best when being pile driven into corner after corner with the utmost aggression.

Gear shifts via the close ratio 6-speed manual transmission are fairly short and sharp and the clutch is well weighted for rapid fire gear changes, but it's not what I'd call an outstanding gearbox. Merely very good.

There's also a flashing red light that blinks excitedly just before you reach the redline that suggests you to slot into the next gear, which is very handy when you cranking up the tempo.

For mine however, the most impressive aspects of the vehicle were tyre and mechanical grip.

While the tyres do a great job of giving you a good feel of the road, it's the steering and suspension geometry and torque-sensitive front and Torsen rear diffs that are the icing on the cake. These elements ensure the tyres almost always have a considerable contact patch with the road, even when the car is being pomelled by strong lateral G-forces through tight, fast corners.

The result is almost comical at times. The WRX STI's steadfast ability to accelerate through bends with such determination - the way it sometimes scrabbles for traction under full throttle when firing out of corners but still holds its line - is hard to describe. 'Awesome' would probably go part-way to relating the sensation.

Though the car does have a tendency to mildly understeer in many situations, where the front outside wheel will tries to push wide, a touch more steering lock and sometimes even a bit more throttle will pull its nose back into line. This isn't a criticism, more an observation. 

And if you want to get technical and tune out some of the understeer, you can always manually adjust the central differential (Multi-mode Driver Control Centre Differential or 'DCCD' in Subaru speak) to apportion more torque to the rear axle via the neat little adjuster switch on the transmission tunnel. There are also three 'auto' settings that bias the front or rear, and can evenly split torque between both axles too.

Tailor-made madness... 

With it's small footprint and tractable AWD power delivery, the level of agility it possesses is difficult to fathom at times. The STI's body is 55mm wider than the WRX model, which further improves its road holding, and the anchors? Excellent.

Measuring 326mm and 316mm front and rear respectively, the ventilated disc brakes are clamped by four pot Brembo calipers at the front and twin piston calipers at the rear, delivering a reassuring initial bite and kidney-popping deceleration when you really squeeze the brake pedal, which is very much a necessity in a four-wheel drive weapon such as this.

With it's incredibly well sorted suspension and direct steering, the car is very communicative as well. As mentioned the 221kW of power and 407Nm of torque can override grip at lower speeds, but you can pinpoint the moment just before the STI is about to arc up, and even when it does start to slide it's quite controllable.

When the VDC, or vehicle dynamics control, is activated it also ensures that the vehicle never gets too out of sorts, and it even has three modes: normal, traction, or completely off.

And just to prove that this modern day hyper hatch is not completely devoid of decorum - and adding yet more options to the tweakability of the vehicles AWD power delivery systems - you can customise throttle response via the SI-Drive, or Subaru Intelligent Drive.

This is the first time SI-Drive has been implemented on an Impreza, and has three settings, Intelligent, Sport, and Sport #. The Sport # setting sharpens throttle response and is best suited to full throttle blasts, while the Intelligent setting is the chilled-out driving mode. It offers much softer response and is best suited to commuting and highway driving and is aimed at reducing fuel consumption, and even tells you when to change gear for optimum efficiency. The Sport mode is a half-way house between the two extremes that never saw any use.

Remarkably, the Subaru WRX STI is not a bad daily driver. When the turbo isn't spooling up and the engine isn't blending vast quantities of oxygen and petroleum for combustion, it's not too bad on the old hip pocket. Because the ride has improved marginally over past STI models, it's a bit easier to live with on a day-to-day basis too.

The hill-holder clutch is a nice touch and because the gear shifts are short and fairly smooth it rarely frustrates, even in built up traffic. The 11 metre turning circle isn't great though, and means U-turns and some parking manoeuvres are trickier than they should be.

It's like this: the Subaru Impreza WRX STI is an immensely satisfying car to drive hard and fast, and very rewarding. It feels more aggressive and more rabid than the last Mitsubishi Evo IX we tested. And that's saying something.

It's an amazing performance car but I must admit that it did take time to appreciate -- and I liked that about it. You can't just get in it and squeeze out 100 per cent performance from the get-go. You have to figure out the car's limits in your own way because it can be an unforgiving car if you get too cocky.

Whether flicking through the gears at a breakneck pace or just cruising through town, the Subaru WRX STI is technological triumph for Subaru, and arguably the most potent turbocharged 4-cylinder car on the market.

Engine: 4.5/5

Generating the kind of punishing acceleration that most people would associate with a high tech roller-coaster, the Subaru WRX STI's horizontally opposed two-and-a-half litre engine is the dogs bollocks.

When the turbo winds up and begins to work its magic, the acceleration is ultra strong and it takes your breath away like few other vehicles. It's one of those rare machines that can keep up with sports bikes in some cases, such is the roll-on acceleration and the way it transfers its power through the wheels.

Weaned on a strict diet of broken glass, radioactive chili peppers and anabolic steroids, the engine is tough as nails and disturbingly powerful.

Displacing 2.5-litres, the 4-cylinder boxer engine gets a number of go-fast technology tweaks, including modified spark plugs, a more efficient air-to-air intercooler, and an upgraded variable valve timing system.

The dual AVCS (active valve control system) works on intake and exhaust valves and is supposed to improve torque generation at lower revs while improving fuel economy. The latter it does with unrivalled success - this thing chews 10.3L/100km on average which is quite surprising - it's even more efficient than the standard Subaru WRX and emits less CO2. Take a bow AVCS.

As for the increased torque at lower revs? I'm not so sure about that, but it doesn't really matter. When the turbo spins up and develops begins to develop strong boost at around 3500rpm, the engine goes into warp drive and your head is snapped back into the cushy leather Recaro pillows and at this stage everything else blurs into insignificance as you focus on the road ahead.

There can be a touch of turbo lag at lower revs when you dial up full throttle, but being in the right gear for the right situation usually stops this from happening. Subaru has also incorporated new quad exhaust outlets, which are supposed to give the car a slightly better exhaust note but when you're driving its the transmission whine and turbo whistle that come to the fore.

With a whopping 407Nm of torque on tap @ 4000rpm from this 4-cylinder boxer engine, the STI can accelerate from 0-100km/h in 5.2 seconds, which bests the previous model STI's 5.4 second dash. It has a top speed of 250km/h.

Peak power is 221kW @ 6000rpm, creating a nice 2000rpm turbo-aided powerband. When you get the engine on the boil and keep the revs above 4000rpm as you row through the gears, the car is violently fast.

Power and torque are both improved by 15kW and 15Nm respectively compared to the previous WRX STI, and as Nick Senior, the Managing Director of Subaru Australia points out, "Third generation Impreza WRX STI is by far the most sophisticated and technologically advanced."

Your ability to fine-tune where the engine's power ends up is one of the coolest aspects of the STI, achieved via the Multi-mode Driver Control Centre Differential (DCCD). 

Via a small switch behind the gear lever you can tailor whether the torque is split equally between the front and rear wheels, or whether it is biased to the front or rear, and there are also 'auto' modes that can increase or decrease the strength of the limited slip differentials.

There are a couple of small issues with the engine however. The first is turbo hesitation. If your gear changes aren't quick enough or you lift off the throttle too long the turbo hesitates and drops off boost, which hampers acceleration and can upset your rhythm.

Another aspect that isn't brilliant are the engine acoustics. It's a fairly soulless sounding engine and the emotional connection that a sonorous exhaust note can bring just isn't there. Next time perhaps.

Exterior: 4/5

With it's wide-body kit, low stance and trademark bonnet scoop, the WRX STI has an imposing look for a vehicle of its size, measuring just 4.41 metres long and 1.79 metres wide.

Long forgotten are the initial misgivings purists had about the new Impreza design, for the WRX STI is a meaty vehicle with plenty of visual fibre.

It has only the bonnet, the roof, and the front doors in common with the Impreza WRX - the rest of the bodywork is unique. It is also the only Impreza that gets mirror-mounted indicators.

The front end of the rally-bred hatch features a wide horizontal air dam below the simple STI-badged grille, and it's this wide expanse of darkness that gives the car machismo. It lends the vehicle a squareness that isn't there in the standard Impreza models and in combination with the extended wheel arches and the chunky 18-inch alloy wheels, the STI's image is impressively aggressive.

There's a number of smaller touches that give the 2008 Subaru Impreza WRX STI an extra element of performance appeal, such as the quad exhaust pipes, the rear diffuser, the roof spoiler and the vertical slots behind the flared front wheel arches.

Xenon headlights and LED brake lights are fitting illuminators for the range-topping car in the Impreza line-up, and on the whole there's not a lot to complain about. The overall profile may not be as sleek or the profile as low as previous Imprezas, but it still has that stocky, muscular, and rather angry look to it that past STI's have made famous.

Interior: 3.5/5

The WRX STI Spec. R test vehicle we reviewed boasted excellent leather Recaro sports seats with extended and firm side bolsters to keep you from moving around during high intensity cornering.

There's plenty of STI badging in the cabin - on the steering wheel, the centre console, the seats, the tachometer etc. - but other than that and the Recaro seats it feels eerily similar to the WRX.

Clearly the $20,000 premium over the WRX goes into the engine and chassis upgrades and not on interior appointments.

Even so, the cabin looks good, showing off a stylish, modern design and even though the dash plastics are unforgiving and harsh, the ambiance is suitably sporty.

Satellite navigation and a sunroof are cost options, but things like drilled alloy pedals, 6-disc CD 10-speaker stereo, climate controlled air conditioning, power windows and mirrors, car security system and a leather multifunction steering are all factory standard.

Crimson instruments, including the speedometer and tachometer (that do the trademark 'Subaru dance' upon ignition) look great at night and the instrument cluster gets digital readouts for the central differential bias and SI Drive systems to let you know what mode the AWD and throttle systems are operating.

I couldn't find a sunglasses holder, which means either I'm an idiot or there wasn't one, and the central arm rest is too low to be of any use.

Safety is naturally very good in this Subaru and like all Impreza models it has six airbags, an advanced passenger safety cell, ABS, brake assist and vehicle dynamics control (VDC), all of which combine to bestow a 5-star ANCAP crash worthiness rating for occupants, and 4-stars for pedestrians.

Overall: 4.25/5

Subaru Technica International has created a technologically advanced sports car that rarely fails to impress, a cornering carnivore with an appetite for apexes.

If it had adjustable suspension, it'd almost be a true rally car and after living with it for a week I have to say this is one of the best value performance cars money can buy.

The 2008 Subaru WRX STI blew my expectations out of the water with its scintillating performance, tough-as-nails character and involving dynamics. Describing what it's like to drive the STI at full tilt is not easy. Sure, it's intensely exhilarating, but there's more to it than that. It provides the kind of adrenaline rush that usually only happens moments before you fall down a flight of stairs. And without the cracked ribs.

While prices start at $59,990 and the Spec. R model fetches $64,990, this is still very good value for money when you consider the blistering acceleration and visceral levels of grip it delivers. 

Thankfully the new Subaru Impreza WRX STI hasn't lost it's edge, and I can happily report that it retains its take-no-prisoners attitude. Like Wesley Snipes, this vehicle is small and sometimes misunderstood, but disrespect it at your peril.