SECTOR Large executive  PRICE TBC  FUEL 44.1mpg  CO2 144g/km

With Efficient Dynamics, BMW has stolen an advantage on its premium rivals with impressively low fuel consumption and emissions figures almost regardless of engine capacity and output. Yet it has taken until 2012 for its first hybrid model to reach the UK (the ActiveHybrid7 sold only in mainland Europe) in the form of this petrol-electric 5 Series.

This month the ActiveHybrid5 goes on sale in the UK, priced at £46,860 and with a comprehensive specification as standard. From the outside it looks like any other 5 Series – save for the rather unsightly badge on the C-pillar and some unique 18-inch alloy wheels – but is still one of the sharper-looking offerings in the class.

BMW says the ActiveHybrid5 is a cleaner alternative to the 535i and the figures back this up. It uses the same 304bhp 3.0-litre TwinPower turbocharged engine with a 53bhp electric motor sandwiched in the housing for the standard eight-speed transmission, giving a total output of 335bhp and 331lb.ft of torque through the rear wheels. With a 2.4-mile pure EV mode at speeds up to 37mph, it does this while returning combined figures of 144g/km and 44.1mpg.

There's very little from the driver's seat to indicate that this is a hybrid except for the modified instrument panel which displays battery charge and ”range boost” to show how much range has been added by the system’s efforts.

The ActiveHybrid5 starts in silence and on a gentle throttle slips straight into EV mode. How the petrol engine kicks in depends on the vehicle settings; BMW's Driving Experience Control has the same EcoPro mode as the 520d EfficientDynamics, which sets all systems for maximum efficiency including electrical convenience systems and the powertrain.

In this mode it takes a more determined squeeze of the accelerator to kick the petrol engine into life, but once activated the acceleration is as brisk as the sub six-second 0-62mph time would suggest. Another useful feature is the ability to switch the engine off on the overrun and decouple from the transmission at speeds up to 100mph.

Driven with efficiency in mind the ActiveHybrid5 is a fuss-free and relaxing experience. The eight-speed transmission is impressive and the switch between power sources is seamless and unobtrusive. Freewheeling at motorway speeds is an odd experience but clearly helps to boost the overall economy. With everything switched into Sport mode the ActiveHybrid5 feels barely different from any other powerful 5 Series; the acceleration is rapid and effortless and despite the extra weight (the battery pack is mounted in the boot) it feels agile – how it copes on the low-friction standard tyres will have to wait for a UK drive.

Christian Schwarz, manager of the ActiveHybrid5 project told us this system will appear in the new 3 Series.

However, there are few other plans for it. He said: ‘This system is too big for the 1 Series, and there are no plans for an X3 or X5 version as the overall weight with four wheel drive would not result in satisfactory performance. The ActiveHybrid system will only appear with this six-cylinder petrol engine; the intention is to offer the dynamics of the 535i without compromises – it drives like a regular BMW rather than an electric car with strong engine braking. Sadly there will be no Touring version of the ActiveHybrid5; the luggage compartment would be too compromised.’

Verdict

The 5 works well as a high-performance hybrid, but EfficientDynamics models have shown people want low emissions with some degree of performance. So this seems an oddly-positioned niche car rather than a must-have, especially with the a 109g/km diesel-electric E-Class hybrid on the way.