USER-choosers will be able to drive what is expected to be the cleanest full-size sports utility vehicle from next summer.

Not only is the car designed with a CO2 emissions target of 150g/km, it will also be one of the quickest off-roaders on sale.

The car is a hybrid version of the RX300. It will retain the 3.0-litre V6 petrol engine, but has additional electric drive at the front. The mechanical rear drive will be ditched in favour of electric drive for the rear wheels. The car can accelerate to 30mph on electric power alone, but for full performance both systems operate in tandem.

When the engine is not being used – for example, while coasting – spare engine power tops up the batteries. When slowing down, the wheel motors are switched to capture energy by regenerative braking, in effect, becoming generators.

Lexus is still two years away from its first diesel, and since the rest of the luxury market is rapidly switching to the black pumps, the company knows its hybrid system will demand a major change in public perceptions.

Stuart McCollough, Lexus director in Europe, said: 'Our job is to make hybrid as mainstream in public awareness as diesel. At the moment, solar power has higher awareness.'

In the long term Lexus, and sister company Toyota, intend to have more hybrid options.