Engine choice - conventional or hybrid ?

The main engine configurations are conventional combustion engines, hybrids, hybrids with hub motors and ultracapacitors, full electrics, and full electrics with hub motors and ultracapacitors.

As the word ‘Hybrid’ suggests, this kind of engine configuration uses both an electric motor and the internal combustion engine to power the vehicle. The main advantages are the use of regenerative braking to recover a part of the kinetic energy back into the battery and the downsizing of the combustion engine while keeping the overall performance the same. There are two different types of hybrid configurations. Parallel hybrids have the electric motor do some of the work in place of the conventional engine. Series hybrids, in contrast use the combustion only to charge the battery which feeds the electric motor. The vehicle is therefore only powered by the electric motor. This has the advantage that the engine acts like a generator and can therefore be operated at constant load close to its most efficient point, enabling greater efficiency. Furthermore, a series hybrid can also drive on electric power only, for example to allow zero emissions in urban areas.