Subaru Cosworth Impreza STI CS400 (2010) revealed

This is the new Cosworth Impreza STI CS400, a limited edition Subaru tuned and tweaked by one of F1’s most famous names. It costs nearly £50k, and will hit 62mph in 3.7 seconds.

Almost – there’s 400PS, so 395bhp in our language; Cosworth removes the 2.5-litre flat-four from the STI and sets about seriously overhauling it. There are different pistons, forged conrods and a higher-pressure oil pump, plus a new turbo, a unique exhaust system, and an ECU upgrade.

Together these extensive changes liberate 33% more power , meaning 395bhp at 5750rpm, up from the standard STI’s 296bhp. There’s 400lb ft too, an increase of 100lb ft, helping the new car hit 62mph in 3.7 seconds (down from 5.2sec). The top speed is limited to 155mph.

To handle the extra power there’s a beefed up synchromesh in the gearbox, plus a short-shift kit and new clutch. And so the chassis keeps up too, Bilstein and Eibach have developed a Cosworth-specific suspension set-up, and dropped the ride height by 10mm. Other major upgrades include a set of AP Racing front brakes with 355mm discs and six-pot callipers, plus a new front bumper and rear spoiler, while more minor stuff includes a smattering of Cosworth badges.

Just 75 Cosworth Impreza STI CS400s will be built, each one will cost £49,995, and sales start in June 2010.

By Ben Pulman