BMW took a big step into the world of green motoring earlier this year with the UK launch of a saloon powered by petrol and electric motors based on German company's successful 5 Series.

In terms of performance the new model - called ActiveHybrid 5 - delivers similar figures to a 535i so it's quick, silky smooth and a joy to drive.

The bonus is in reduced fuel consumption and carbon dioxide emissions resulting in a significant reduction in company car tax. 

The star of the ActiveHybrid 5 show is an intelligent energy management system.

Using an advanced satellite navigation set up, the car is able to read the road ahead and prepare the engine and electrical systems to respond in the most efficient way.

So if you are approaching a hilly stretch of road, energy is stored in the battery so the electric motor is ready to assist when more power is needed.

The ActiveHybrid 5 combines the 3.0-litre TwinPower Turbo petrol engine of the 535i with an electric motor linked to an eight-speed automatic gearbox which can cater for either cruising on the motorway or rapid acceleration with equal aplomb.

The car flits between power sources but, unless you're looking at the natty digital display on the dashboard which tells you what mode the car is in, the changes are seamless.

At speeds of up to 37mph the ActiveHybrid 5 can travel on electric power alone for up to 2.4 miles - thanks to the high-performance battery stored in the boot. 

There is a price to pay on luggage space - but there is still 375-litres to play with which is ample for most families. The battery is charged whenever the car is braking while the automatic start-stop function switches off the petrol engine when you come to a standstill - for example at junctions or at a red light.

The atmosphere in the cabin is unaffected though as the climate control system continues to operate via battery power.

The petrol engine comes into play when more power is needed or the energy stored in the battery is exhausted.

Hybrid cars are not always the quickest off the mark but BMW ensures the ActiveHybrid 5 boasts a 0-62mph of just under six seconds - the same as the 535i. And with a combined fuel consumption figure of 44.1mpg, a carbon dioxide output of 149g/km and a benefit-in-kind rate of 19 per cent it has a clear edge on its sibling when it comes to running costs.

The ActiveHybrid 5 is a joy to drive thanks to a super supple suspension, sharp steering and the balance of a gymnast.

The interior features a fit and finish which are top notch and at journey's end I found myself unwilling to leave the cabin's embrace. 

The driving position is superb thanks to electric adjustment for the seat height and backrest angle.

The dashboard is a dream with the many functions available via the iDrive rotary controller able to be viewed on a central monitor.

It's probably quicker to list the equipment the ActiveHybrid 5 isn't fitted with - for example no rocket launcher or swimming pool are included.

But with all mod cons supplemented by a natty head-up display that projects vital information on to the windscreen in the driver's line of sight the last thing you will feel is short-changed.

It's not cheap but then again it is a high-class hybrid.