If the car is 100% electric, then its electric car emissions are zero. Electric cars that emit greenhouse gases like carbon dioxide probably include a gasoline engine. In this case, the car is considered a hybrid. Still, hybrid electric cars release 80% less pollutants and gases than a conventional gasoline engine vehicle. However, emission rates for a hybrid is not the same from car to car. For example, emissions from a Toyota Prius have been rated at 3.5 tons a year, while emissions for a Honda Civic hybrid have been measured at 4.1 tons a year.