Multiple studies have found that electric cars are more efficient, and therefore responsible for less greenhouse gas and other emissions than cars powered solely by internal combustion engines. An EU study based on expected performance in 2020 found that an electric car using electricity generated solely by an oil-fired power station would use only two-thirds of the energy of a petrol car travelling the same distance.

For every 100km travelled in a petrol car ... ... it takes 26 megajoules to get petrol out of the ground and transport it to the car ... ... and the car itself uses 142 megajoules to move itself around. For the same distance in an electric car, using electricity generated in an oil-fired power plant ... it takes 74 megajoules to generate and transport the electricity to the car ... ... which then uses just 38 megajoules to move itself and its passengers

Although an electric car powered in this way is still ultimately burning the same fuel as the petrol car it replaces, it is burning much less of it. And although greenhouse gas emissions are similarly harmful wherever they occur, some other emissions which are harmful to human health are less dangerous when they happen at a power plant outside the city than at the roadside near schools and houses.

There are many different types of electric vehicle

The distinction between petrol and electric is not binary; a car's green credentials vary according to whether and how it uses electricity, and how that electricity is generated, with important trade-offs for efficiency and range.