THE number of plug-in models being offered by BMW in its 3 Series range is to increase to four in the coming months with the announcement that PHEV technology will be introduced on estate variants and with all-wheel-drive options available.

The new cars will be unveiled at the Geneva Motor Show in March and will be on the road in the summer.

BMW has also revealed it will be showing off more electrified models at Geneva where it will be displaying M340d xDrive versions with 48-volt mild-hybrid powertrains in both saloon and estate body styles.

At the moment, the Bavarian car maker offers only the 330e saloon as a plug-in.

The saloon is rated officially at up to 201mpg which results in an emissions figure of 32g/km at best and the new Touring versions are said to have fuel figures of up to 176mpg with emissions of 39g/km.

Prices for the new models are still to be announced but the 330e currently carries a premium of some £4,000 over conventional versions and the 330e saloon costs from £39,980.

The plug-in models are said to have a zero emission range of up to 36 miles and can be recharged to 80 per cent battery capacity in less than two-and-a-half hours using a BMW wallbox.

Provisional performance figures for the new 330e Touring are 0 to 60 acceleration in around six seconds with a top speed of 136mph and the car can travel at motorway speeds on electric power alone.

Fuel economy figures for the xDrive four-wheel-drive versions are 166mpg for the saloon and 156mpg for the estate models.

The new mild hybrid M340d models have sub-five second 0 to 60 acceleration times and fuel consumption rated at around 53mpg with emissions as low as 139g/km for the saloon - an improvement of almost 30g/km over the non-hybridised version. The Touring variants are slightly less economical.

Prices for the new cleaner powertrain options on the 3 Series are still to be announced.