Geneva motor show 2012: BMW M135i

BMW is set to crown its second-generation 1-series line-up with this exciting new 300bhp plus six-cylinder powered BMW M135i model, which has been unveiled at the Geneva motor show.

The Audi RS3 rivaling hatchback, planned for UK sale before the end of 2012, forms part of BMW’s new M Performance line-up, joining the recently revealed M550d xDrive saloon and touring, X5 M50d and X6 M50d.

It is also the first three-door version of BMW’s second-generation 1-series that is set to be sold with the same range of four-cylinder petrol and diesel engines as its more practical five-door sibling from mid-year.

Although not a fully-fledged M-car, the M135i draws heavily on the year-old M135i Coupe, sharing its engine and gearbox among other go-fast components.

Full details are yet to be revealed, but BMW insiders hint the new hatchback’s twin-turbocharged 3.0-litre in-line six-cylinder engine, the M54S as it is known internally, kicks out in the region of 320bhp, together with 332lb ft of torque.

Unlike the rear-wheel-drive only M135i Coupe, though, Autocar can reveal that BMW plans to offer the new M135i hatchback with both standard rear-wheel drive and optional four-wheel drive. But like other non SUV xDrive models sold by BMW, the upcoming M135i xDrive is likely to come in left-hand drive form only, ruling out UK sales of the four-wheel drive version.

With a rumoured 1500kg kerb weight and power-to-weight ratio described as being better than 220bhp/tonne in rear-wheel drive guise, Munich’s new hyper hatch is expected to deliver performance comparable to the M135i Coupe – 0-62mph acceleration in 4.9sec, 0-124mph in 17.3sec and a limited 155mph top speed.

Allied to the upgraded driveline is a heavily reworked suspension with wider tracks, lower ride height and larger 18-inch wheels than standard 1-series models. BMW describes the handling as offering “a noticeable improvement in overall agility and more precise characteristics”. The brakes have also been upgraded, with 360mm rotors appearing up front and 350mm units at the rear.

As previewed by the concept at Geneva, the M135i will receive a distinctive body kit to differentiate it from other less powerful three door 1-series hatchback models. Included is a deeper front bumper boasting typical M division styling cues, LED imbued headlamps, unique mirror housings, wider sills under the doors and a substantial rear bumper featuring a black lower section and twin tail pipes.