The Volkswagen Golf...

The Volkswagen Golf is ready to join the hybrid club! The German company will unveil a new diesel-electric version of its best-selling hatchback at next month’s Geneva Motor Show.

Set to be the most efficient and cost-effective model in the line-up, the Golf will return an incredible 83.1mpg and emit only 89g/km of CO2.

Unlike the Toyota Prius and Honda Civic IMA, the newcomer will use an oil-burner instead of a petrol engine as its main source of power. While no details have been officially released, the unit in question is expected to be the common-rail 2.0-litre recently launched in the Tiguan SUV, as it will need to meet strict Euro V emissions rules.

Driving the front wheels, this powerplant will be boosted by an electric motor that not only gives extra performance, but could allow the car to run on its battery only at low speeds, too.

The Golf is also likely to get a modified version of VW’s efficient, quick-shifting DSG double-clutch transmission. In addition, engineers will fit a stop-start system to cut the engine when the car is stationary.

Further fuel-saving measures will include regenerative braking and aero-dynamic tweaks similar to those seen on VW’s efficient Bluemotion models. For now, only Peugeot has a potential rival for the VW. The French marque unveiled its 308 Hybride HDi at last autumn’s Frankfurt expo, and plans to bring it to dealers by 2010. Mating a 110bhp 1.6-litre diesel with a 22bhp electric motor, the family hatchback is capable of returning 83mpg economy, and puts out only 90g/km of CO2.

The first hybrid Golfs are expected here late next year. And the innovative drivetrain will find its way into other VW Group cars, including Audi’s A3.