By Matt Joy, Press Association

WHAT'S NEW?: From the outside, there's almost nothing to distinguish the PIH from any other 3 Series - and that's exactly the intention. Designed to fit neatly into the rest of the range rather than being a standalone model, the 3 Series PHEV has all its changes under the skin.

Under the bonnet, there's a new generation 2.0-litre turbocharged petrol engine delivering 180hp while, at the rear, there's a substantial battery pack powering an electric motor up front to give a combined total of 245hp, using technology derived from that used in the i3 and i8 pure electric vehicles. The aim is to deliver performance in line with the 328i model, but with substantially better fuel consumption and emissions.

LOOKS AND IMAGE: If you want to know what the 3 Series looks like, then just peer out of your window; it's the archetypal compact sporting saloon with its short front overhang, square-jawed nose and generally slightly aggressive demeanour. That's exactly what the thousands of people who buy one every year want however, and despite the changes underneath, you won't be able to tell the PHEV version from any other - apart from the badges of course.

SPACE AND PRACTICALITY: Adding a load of bulky technology to an existing car comes at the cost of space, but BMW has done a good job of minimising the impact. The only noticeable change is in the boot, under which sits the battery pack and associated components. The upshot is the boot floor is raised by 35mm, and while that's obvious reduction, the boot still looks pretty spacious.

BEHIND THE WHEEL: A lot of thought has been put into making the PHEV drive as well as a regular 3 Series and be able to suit all kinds of driving conditions, so there are a number of modes that change the whole operation of the system.

Start it up and it operates silently, going straight into pure EV mode unless the temperature is below 10 degrees Celcius. You can switch between Comfort, Sport and EcoPro modes as normal and this will vary the operation of the engine; either being silent unless required, working with the electric motor for maximum performance or being used as a range extender when required. Even better is the Proactive Driving Assistant which scans your route if you've used the sat nav and switches the driving mode for you for maximum efficiency.

The upshot is that the 3 Series PHEV drives with the same responsiveness and vigour as the standard car; acceleration is pleasingly brisk in pure electric mode and usefully rapid when motor and engine combine. It remains great fun to drive at pace too, with no apparent compromise.

VALUE FOR MONEY: This is still a prototype of course, so prices and specification are some way off. However BMW has said that it will be priced close to the equivalent petrol and diesel models, which could make it the pick of the range; fuel economy and emissions better than the diesel with performance on a par with the sporty 328i petrol.

WHO WOULD BUY ONE?: The potential audience for a plug in hybrid 3 Series is sizeable. If you're sufficiently open-minded, then there's no reason why you couldn't ditch regular diesel or petrol power for the hybrid option, and although it would be slightly less efficient, it's not essential to plug it in at home every night as the battery can be charged on the move. It's still going to cost more than £30,000 of course, but potentially it offers running costs far below those of a conventional 3 Series, as well as being much cleaner at the tailpipe.


IF THIS CAR WAS A...: Taxi, it would be fast and low emission


BMW 3 Series PHEV Prototype, £35,000 (est)

Engine: 2.0-litre petrol unit and electric motor, combined 242bhp and 295lb/ft of torque

Transmission: Eight-speed automatic driving the rear wheels

Performance: Top speed 155mph (est), 0-62mph in 6.0 seconds (est)

Economy: 130mpg combined

Emissions: 50g/km of CO2