SUBARU’s Impreza STi is an icon. A legend. Years from now it will be remembered in the same way as past heroes, such as the first Golf GTi, Renault Gordini and original Mini Cooper. But unlike these cars, the Impreza STi shows no sign of fading away, or growing up. Every year it becomes faster. Wilder. Crazier. You can thank Subaru for that, for this is a very stubborn company that seems to completely ignore automotive fashion, and fiddles instead with the bits that make a car more exciting to drive.
The most important news with this, the ninth interpretation of the “gold rims and big wings” theme, is the fitment of a 2,5-litre flat-four engine, in place of the previous 2,0-litre. The reason for the fitment of a larger capacity engine is not for increased performance, but rather to improve drivability. Still, power is up by 11 kW to 206 kW, developed at 6 000 r/min, while torque has improved by 14 per cent, to 392 N.m. There certainly is less lag than before, and the STi feels keener to react to throttle adjustments, especially around 3 000 r/min.
The engine features several refinements, most of which are aimed to improve emissions levels, economy and refinement. An electrically driven, secondary air pump is fitted, which supplies ambient air to the exhaust ports during cold starts, resulting in the ignition of any residual unburnt fuel and thereby reducing hydrocarbon emissions. There is also a non-return fuel system, of which one advantage is cooler fuel. The exhaust system is new, with a significantly larger main silencer. And, finally, all Imprezas now feature resin-liquid engine mountings, which are claimed to benefit both noise and vibration levels.
Power goes to all four wheels via Subaru’s rally-honed six-speed manual shift gearbox, which benefits from the fitment of carbon-plated synchromesh rings on the top three gears.
The ’06 STi features an improved driver controlled centre differential (DCCD) system, which allows drivers to set up the car’s torque-split to suit their driving style or the road conditions. With this latest DCCD, the static torque split has changed from 35:65 (front/rear) to 41:59. A steering angle sensor has been added to provide more information to the control unit of the electromagnetic clutch, which decides on the torque split when DCCD is left in Auto mode.
DCCD now also features a camtype limited-slip differential that is said to generate a thrust force to activate the differential, thereby improving stability.
Quite a lot of small changes, then, but they combine to make a significant overall improvement.
Due to the general unavailability of 97-octane petrol, this was the first STi for some time that we have tested running on 95 octane and, as a result, the improvements may not be as easy to spot in our test results. But they certainly are there. Most obvious is the new car’s ability to reach a limited top speed of 253 km/h. Better aerodynamics and revised gearing have added to this improvement.
Due mainly to different gearing, our overtaking acceleration times aren’t much different from the old car’s. The same can be said of the 0-100 km/h sprint time that, at 5,31 seconds, is 0,1 slower than previously. However, the new car is comfortably faster over a kilometre (24,79 sec).
Suspension, brakes and steering systems have not been changed much – not that much needed changing.
The feel-good starts when you turn the key and watch the dials do their “preparation dance” before the engine bursts into life with that typically metallic, raspy Subaru flat-four beat. With little noticeable turbo lag, power delivery is intense – it just picks up and multiplies as the revs rise. If it all sounds tame… let’s explain it this way.
From zero to 60 km/h the Impreza is faster than a Ferrari 360 Modena. From 60 to 80 km/h, it’ll kill a current Porsche 911 Carrera S. And from 80 to 100 km/h, that poseur in his Lamborghini Gallardo will be hugely Intensity of power just picks up and multiplies embarrassed. Not convinced? Well, to put it graphically, the Impreza STi can easily accelerate your sunglasses off the top of your head…
Fast it certainly is. But it has an even bigger talent. Big improvements in steering feel and response were made at the time of the previous facelift, and this new one feels even better. The steering is now super quick, if a little light in initial feel. The revised torque split has not resulted in more understeer, as you may have expected. And the LSD keeps torque steer in check. The overall effect is that it is now easier to drive the Impreza with precision.
Gravity-defying grip was always the car’s “get out of jail free” card, and remains one of the its greatest assets. But if you really want to get the tail out, you can do so by dialling the maximum amount of torque to the rear.
Overall, the way the Impreza spears into a corner, barrels through it, and then tears up the next straight, remains an experience that will leave you breathless and wildeyed. And at that moment you’ll forgive it any of its aesthetic sins…
Test summary
Power alone is not what makes the Impreza STi so impressive. Nor is it the phenomenal roadholding. It is the way the Impreza “forces” the driver to be an active part of the driving experience, and rewards him/her for the dedication. As a result, it is a hugely engaging machine, and one that remains an interesting drive even after you’ve done it a hundred times. Let’s hope Subaru doesn’t cave in to fashion and make the next one soft and mature, for the automotive world would be much poorer without this crazy, but hugely capable, character of a car.
