The gains in the pre-homologation figures are said to be the result of improving the thermal efficiency of the 1.8-litre petrol engine – in other words reducing the energy lost as heat during the combustion cycle – as well as modifying the transmission.

The electric part of the drivetrain includes a more compact, more energy-dense nickel-metal hydride battery and a motor which now provides more assistance while accelerating, which reduces the springy quick-rev, slow acceleration characteristics of the old car. For the first time, the Prius can tow an unbraked trailer of up to 725kg.  

Performance improvements see the new Prius accelerate from nought to 100kph in 10.6 seconds. Highway overtaking acceleration from 80 to 120kph is 8.3 seconds and the top speed is 180kph.

Toyota has also improved the rigidity of the bodyshell by 60%, as well as improving aerodynamics to reduce fuel consumption. It’s claimed that this makes the latest Prius more fun to drive.