The hybrid version of the BMW 5-series has been spied testing.
BMW’s first hybrid saloon will come with a straight-six petrol engine and be able to run on electric power alone.
A concept version of the car, the Active Hybrid 5-series, was unveiled at this year's Geneva motor show, and the production model is expected to go on sale next year.
The concept was fitted with a 40kW/52bhp electric motor sandwiched between the engine and the eight-speed automatic transmission.
The car is said to improve fuel consumption and reduce CO2 emissions by 10 per cent compared with a conventional six-cylinder 5-series.
It can also tailor the performance of the hybrid system by using the sat-nav to predict obstacles such as hills, corners and traffic obstructions that could affect the battery life.
By doing this, the car can charge the battery during the journey and then turn off the engine before it reaches its destination, finishing the trip on electric power alone.
BMW says this technique extends the electric-only range by up to 30 per cent.