BMW has launched PHEV versions of its 7-Series with two- or four wheel drive.

The plug-in hybrid system for the 745e and long wheelbase 4WD variant combines a six-cylinder in-line petrol engine and higher capacity battery for a boost in power output and torque, as well as improved figures for electric range, fuel consumption and CO2 emissions.

The three-litre I6 has peak power output of 286hp combined with an electric motor rated at 113hp and torque of 265Nm. In Sport mode, the two power sources combine to give a total power output of 394hp and maximum torque of 600Nm.

A preview function works with the car's GPS to assign electric power most efficiently on a pre-planned route.

The new lithium-ion battery has an increased capacity of 12.0kWh. In Hybrid mode, all models can travel at up to 68mph – 13mph faster than the predecessor models – in purely electric mode. The petrol engine doesn't join in until the car reaches the higher speed, or the engine is under particularly heavy load. In Electric mode, the power of the electric motor alone is sufficient to reach a speed of 87mph.

The 745e has a maximum electric range of between 34-36 miles depending on driving conditions while the 745Le xDrive offers 32-34 miles.

Fuel consumption and emissions have also been improved. For the 745e, combined consumption is between 141-123mpg on the NEDC cycle. CO2 emissions are from 48g/km.The 745Le xDrive gets 118-105mpg and emits 52g/km.

The electric motor is integrated into the eight-speed Steptronic transmission and acts as a generator during braking and coasting, feeding regenerative energy back into the battery. The lithium-ion battery also powers the car's on-board network and can be used to run the auxiliary air conditioning system.

The battery is positioned underneath the rear seats while the 46-litre fuel tank is above the rear axle. Luggage compartment volume is thus only slightly restricted.

From summer 2019, new digital services will be available to make charging the battery en-route more convenient. When selecting a public charging station, the navigation system also provides the driver with a list of recommended nearby hotels, restaurants, cafés and tourist attractions. The driver is also provided with a charging station occupancy forecast.