An aerodynamic body is also a major factor. The drag coefficient of 0.25 is among the lowest in the world. This means the new Toyota Prius cuts through the air with less resistance - so less fuel is needed to maintain speed. MSN Cars also feels the new shape is attractive on the eye and modern.

Inside, there's a host of eco-gadgetry to help the driver achieve best miles-per-gallon. Toyota says these are 'unique', and will mirror the eco-meter as seen in the Honda Insight. They'll be shown on a head-up display. Toyota has also fitted a solar-powered ventilation system that cools the cabin when parked up.

Prices have not been announced, but they will not be as low as the Honda Insight's headline-grabbing £15,490 level. Today's Toyota Prius starts at just under £18,000. But it will enjoy free road tax, plus other big advantages from its low CO2 figure. That it's also so exceedingly fuel-efficient will also save pounds, when it hits dealers in July!