VW?s Golf turns a green shade

The Golf TDI Hybrid uses a diesel engine returning 3.35 litres/100km and 89g/km of CO2.

The hybrid combines an advanced diesel engine with an electric motor and the latest generation of seven-speed DSG gearbox.

Around town, the Golf TDI Hybrid reverts to purely electric mode to be emission-free.

At the core of the new Golf is a highly efficient 1.2-litre three-cylinder common rail TDI diesel engine developing 100kW and 180Nm of torque.

Working either in tandem with the diesel engine or, if required, on its own, is an electric motor developing 20kW and 140Nm of torque.

The electric motor also replaces the conventional starter motor and alternator to save weight and improve packaging. It can also operate as a generator, recovering kinetic energy from the car during braking to charge the 220-volt, 45kg nickel metal hydride battery which has a capacity of 1.4kW hours.

In practice, the electric motor powers the vehicle from standstill with the diesel engine only engaging should additional acceleration be required or at higher speeds.

In these situations the diesel engine takes over with the electric motor only working if required to supplement the combustion engine – for example, during overtaking manoeuvres.

When at a standstill the diesel engine shuts down completely to conserve fuel and increase efficiency.

Drive on the concept car is channelled through the new seven-speed DSG twin-clutch gearbox.

This features a pair of dry clutches as opposed to wet (lubricated) clutches and sets a new energy efficiency standard for automatic gearboxes.

Visual changes which differentiate the Golf TDI Hybrid include a new grille design, smaller front air intakes to reduce aerodynamic drag and subtle TDI-Hybrid badging.

The Golf TDI Hybrid also sits lower than the standard Golf on revised suspension and adopts the front splitter from the Golf GTI Edition 30 to help further reduce aerodynamic drag. The interior further distinguishes the Golf TDI Hybrid from the conventional vehicle.

The Golf TDI Hybrid is a concept vehicle, but a version is likely to go into production in the future.

This study follows the recent launch of the efficient new Golf BlueMotion.

Adopting an optimised 1.9-litre, four-cylinder diesel engine linked to a revised gearbox and more efficient aerodynamics the Golf BlueMotion can achieve a combined 4.4 litres/100km, while emitting just 119g/km of CO2, meaning it will be exempt from the London Congestion Charge from October 27 onwards.