Cosworth and Impreza. For car fans, mere mention of these names quicken the pulse. Put them together and the excitement spirals.

And the result is the Cosworth Impreza STi CS400. If you’ve its £49,995 asking price, this’ll be the first genuine Cosworth-developed road car since 1996 you could buy.

For that you’ll get a 394bhp, four-wheel-drive car that’ll gallop to 62mph from rest in just 3.7secs. And it’ll be one of just 75 to be sold in the UK, Subaru promise. While the car’s a third again more powerful than the fastest production Impreza, the WRX STi, Cosworth’s brief was to keep changes simple and efficient so that the car could be serviced by any of Subaru’s regular dealers.

Changes to the engine include high-performance pistons, manufactured in the same way as those for a Formula 1 race car. Upgraded head gaskets and a higher pressure oil pump also contribute towards a huge increase in power output, particularly as the revs climb.

The car also has an all new Cosworth-designed turbocharger and a unique exhaust which ‘breathes’ more easily. To handle the extra urge, the six-speed manual gearbox is made tougher and features a shorter ‘throw’ for quicker shifting. The clutch is upgraded, too.

The transmission divides output equally between the front and rear wheels as standard but adjusts the power as road and driving conditions dictate. The car’s suspension layout and major components are retained but the car rides 10mm closer to the ground at the front, while the coil springs and dampers are made to Cosworth’s specifications.

This, it is claimed, improves the ride comfort, actually making it easier to live with day to day than the standard car . But the changes allow it to enter corners flatly and carry more speed.

Front brakes are more powerful than on the standard car, using motorsport-style six-point callipers but the car’s standard rear brakes and anti-lock system is retained.

The car has a new front bumper and rear spoiler, lighter and stronger alloy wheels while inside it the Recaro seats are re-trimmed in Cosworth-branded black leather. The cabin is well stocked: satellite navigation, push-button start and a 10-speaker stereo are standard as are six airbags.

The car comes with a three-year Subaru warranty although this carries a limit of just 36,000 miles. The cars go on sale from June. Pick between Spark Silver, Dark Grey or San Remo Red.