BMW will officially unveil the third model in its 4 Series range, the Gran Coupe, at the Geneva motor show next month.

Although described as a four-door coupe, with its liftback tailgate it’s actually closer to a five-door hatchback.

Power comes from a choice of five engines: three petrol and two diesel.

The range kicks off with the £29,420 420i, powered by a four-cylinder petrol unit with 184hp and 270Nm of torque, enough to achieve 0-62mph in 7.4 seconds.  Fuel economy is officially recorded at 44.1 mpg for manual and 46.3 mpg for automatic models, while CO2 emissions are 149 and 142 g/km respectively.

The £32,815 428i uses the same 2.0-litre unit as the 420i, but the addition of a turbocharger increases power to 245hp and torque to 350Nm.  The 0-62mph dash is taken care of in 6.1 seconds, while economy remains largely unaffected at 42.8 mpg (44.8 auto) with CO2 emissions of 154 g/km (147 auto).

The £41,155 range-topping 435i features a 3.0-litre six-cylinder unit producing 306hp and 400Nm of torque, enough to sprint to 62mph in 5.5 seconds (5.2 for the auto).  Its green credentials do take a small hit, with economy of 34.9 mpg (37.3 auto) and CO2 emissions of 189 g/km (174 auto).

Diesel options come in the form of the £30,995 418d with 143hp and 320Nm, with a 0-62mph figure of 9.2 seconds (9.1 auto), economy of 61.4 mpg and CO2 emissions of 121 g/km.

The £31,795 420d boosts power to 184hp, torque to 280Nm, and the 0-62mph time to 7.7 seconds (7.5 auto).  Economy slips by the slightest of margins to 60.1 mpg (61.4 auto) and CO2 emissions to 124 g/km (121 auto).

A four-wheel-drive 420d xDrive model will be offered for £34,795, while a 313hp six-cylinder 435d xDrive and a 258hp 430d model will arrive in July.  BMW’s xDrive system will also become available on the 420i later.

Six-speed manual transmissions are standard, with the option of an eight-speed automatic across the range.

The 4-Series Gran Coupe has the same exterior dimensions as the two-door coupe, although the new roof-line makes it 12mm higher.

The rear seats, although styled as two, can accommodate a third-seat passenger, and fold with a 60:40 split to increase boot space from 480 litres to 1,300 litres.

Access is through a powered tailgate that can optionally be opened by waving a foot under the rear bumper.

BMW says the spring and damper rates have been revised while additional strengthening maintains body stiffness and therefore handling.

UK models will match the specification of the 4-Series Coupe, with front and rear parking sensors, heated front seats, Xenon headlights, leather upholstery, cruise control, Bluetooth, DAB digital radio and other goodies.

The new BMW 4-Series Gran Coupe goes on sale on 21st June 2014, with prices starting from £29,420 rising to £41,155.