Subaru Cosworth Impreza STi CS400

SUBARU and Cosworth are two of world rallying’s most evocative names, so the latest Impreza promises to be the best yet. As well as a 395bhp 2.5-litre boxer engine, it has lightweight alloys, revised styling, Bilstein suspension, a wider track and AP Racing brakes.

On paper the changes are a huge success, because the Subaru set the eighth fastest time around the Anglesey track. Look at the final rundown and that puts it just behind the BMW M3 and in front of heavyweights such as the Mercedes E63 AMG and Bentley Continental Supersports. The trick four-wheel-drive set-up plays a big part here. Traction is mightily impressive and, if you keep your throttle foot planted as you exit corners, you can feel the power shuffling between the axles as it works out the best distribution.

So how come the Impreza takes the wooden spoon? Well, proceedings are dominated by the engine’s massive turbo. It’s so big the power delivery is interrupted by tremendous lag as it spools up. Below 3,000rpm, there’s surprisingly little punch, so you must wait for the revs to build before the massive explosion of muscle.

On the track you can drive around the problem to a certain extent, but the engine’s narrow powerband still makes it difficult to keep on the boil. And on the road things are even worse. Move out to overtake a slower car or exit a corner expecting instant acceleration, and you could find yourself in for a long wait…

Impreza enthusiasts will no doubt love the cacophony of noises from the engine – you can hear the air being sucked in and a loud hiss as the turbo dumps unwanted boost pressure whenyou change gear or lift off the throttle. But it’s not exactly refined.

Only 75 examples of the Impreza Cosworth will be built, yet with a £50,000 price tag, only hardcore Subaru fans need apply.