Why two-motor hybrid systems are better than those with just one

2017 Toyota Prius Prime PremiumSix years ago, we wrote that a number of single-motor hybrid systems were about to enter the market. They represented a new approach to a technology pioneered in 1997, when the first-generation Toyota Prius was launched in Japan. Through 2010, all the full-hybrid vehicles introduced by Ford and General Motors used systems designed around a pair of...