Priced from £30,145 OTR, first customer deliveries will take place in spring 2011.

There will be a choice of four efficient engines at launch – one petrol and three diesel – teamed with manual, multitronic or S tronic transmissions, while a hybrid 2.0-litre TFSI petrol engine with an electric motor delivering 45.6mpg and 245bhp will arrive later.

Of most interest to fleets will be the 177bhp 2.0-litre TDI allied to six-speed manual transmission, which will return 57.7mpg according to the combined cycle test and 129g/km.

Aluminium will account for around 20% of the surface area of the car, resulting in lower weight of less than 1,600kg. In addition, the use of direct-injection technology, a start-stop system and energy recovery means that fuel economy has improved by up to 19% compared to the previous model.

Two specification levels – SE and S line – will be offered in the UK, each including alloy wheels, leather upholstery, cruise and front and rear parking controls, SD-based satellite navigation, Bluetooth phone preparation, split/folding rear seats and light and rain sensors.

S line models will add larger 18-inch alloy wheels, xenon headlamps with LED daytime running lamps, sports suspension, upgraded Valcona leather upholstery and an exclusive S line exterior and interior styling treatment.

From the options list customers will be able to choose features such as comfort seats with heating, cooling and massaging functions, acoustic glazing, supple leather trimming for the centre console, a 15-speaker Bang & Olufsen audio system with 1,200 watts of power, TV reception and various connectivity upgrades for the MMI system.