An all-electric vehicle might produce 50% more greenhouse gases than a non-plug-in Prius, according to a study to be released tomorrow by the Union of Concerned Scientists. It depends on the mix of electric energy sources. A preview article in today's (April 15) New York Times reports that in Los Angeles a Nissan Leaf would emit the greenhouse gases of a 79 mpg gasoline car. In Denver, where electricity depends on coal generation, the Leaf is as dirty as a 33 mpg gas car. The map accompanying the article can tell you whether your PIP will be responsible for more greenhouse gases in EV or HV mode. Better figures might be available when the study is released tomorrow.