 The study found that there are no regions in the U.S. where plug-in electric cars will have higher greenhouse gas emissions than the average new compact gasoline engine automobile, and the area with the dirtiest power supply produces emissions equivalent to a gasoline-powered car rated at .The following table shows a representative sample of cities within each of the three categories of emissions intensity used in the UCS study, showing the corresponding miles per gallon equivalent for each city as compared to the greenhouse gas emissions of a gasoline-powered car