Given the recent launch of an all-new Toyota Prius, this one built on an entirely new platform, the followup of a plug-in version should come as no surprise. Yet the 2017 Toyota Prius Prime, launched at the New York Auto Show, doubles the electric range of its predecessor, and claims an efficiency figure of 120 miles-per-gallon -equivalent (MPGe).
For power, Toyota augments the new Prius Prime's 1.8-liter gasoline engine with an electric drive…