Research from the University of Rome has found Toyota's Prius runs on electric power and with zero exhaust emissions for the majority of the time on busy commuter journeys, .
Data gathered from more than 1,360 miles of driving on a typical Rome commuting journey reveal that the test Prius cars spent an average 73.2% of the journey time (62.5% of the journey distance) producing no tailpipe emissions.
These figures included periods when the car was stationary, with the engine automatically switched off.
In urban areas, Prius achieved zero emissions for 79.4% of the journey time and 76.3% of the route distance.
Almost 45% of the car’s drive power was sourced from the electric motor, with 34.3% of its electric energy produced by the regenerative braking system. Thus, more than one third of the electric power used to drive the wheels of the test cars was produced simply by the act of braking or slowing down.
The study project, commissioned by Toyota Motor Italy, used a team of 20 drivers, evenly divided between men and women in age groups up to and over 35.
There was an equal balance between those who had driven a hybrid car before, and those with no experience.
Each participant drove the same 37km route across Rome and back, at three different times of day – morning, afternoon and evening – using a standard Prius fitted with 17-inch wheels.
For each journey the Eco drive mode was selected and the air conditioning was switched off; speed limits were observed at all times.