GM promises it can make money on all-electric cars by 2021

2017 Chevrolet Bolt EV pre-production vehicles at Orion Township Assembly Plant, March 2016Radically new powertrains are widely assumed to lose money for the companies that launch them. Toyota's hybrid-electric system, launched in Japan in 1997, likely didn't break even until sometime after the 2004 launch of the second-generation Prius. Long-range battery-electric vehicles are the same, according to analysts and insiders: the question...