This configuration enables the power to be split into an electrical and a mechanical path. Conventional one-mode hybrid systems tend not to have mechanical ratios. As such, this kind of system transfers the bulk of the power via the electrical path with high electrical output and hence lower efficiency. It works efficiently principally at lower loads and speeds. If power also needs to be transferred at higher loads and speeds, an accordingly larger electric motor would be required. Having to power and find space for this engine would only be possible at the expense of efficiency. In response to increasing engine loads and higher speeds, two-mode technology, by contrast, variably shifts the power transfer from the electrical path to the mechanical drive path. As a result, the system is much more efficient in all situations, both in inner-city stop-and-go traffic as well as on fast motorway journeys, while also enabling smaller electric motors to be used. The efficiency boost - both in urban traffic as well as on motorway journeys - is therefore where "two-mode" technology gets its name from.
