The US EPA Says The Chevrolet Volt is Barely Greener than The Toyota Prius

What about the plug-in Prius Prime? Even in dirty grid Akron, the Prime beats the national average for the Volt, and its national average is just 170. Though its 25-mile range is less, it is more effeicinet on gas and electricity with 54 mpg, and 133 MPGe / 25 kWh/100 miles.