CO2 emissions for the latest generation Toyota Prius are to start from 70g/km, subject to final tests.
Fuel consumption figures are up to 94.2mpg, compared to the 89g/km and 72.4mpg achieved by its predecessor.
The increase in efficiency has been achieved through the introduction of the TNGA (Toyota New Global Architecture) platform.
A new PCU (Power Control Unit) allows the system to draw more on its electric power, which means that acceleration feels more natural with the engine revs building up gradually as the car gathers speed.
This fourth generation Prius is the first that is able to pull a trailer, thanks to its 725 kg unbraked towing capacity.