The engine achieves half the petrol consumption of a conventional petrol-engined car of similar performance in urban conditions. The key to the mechanical efficiency of the vehicle is its ability to ensure that energy is conserved at all times, instead of going to waste. The main function of the engine is to drive the wheels, but any excess output is used to recharge the batteries.
There are no plans to bring the Prius to Europe - although Toyota executives say it could happen in the future. Fleet customers, in particular, would be the main beneficiaries of any launch in the UK.