 The redesigned and more efficient fourth generation Prius was released for retail customers in Japan in December 2015.The 2016 model year Prius Eco surpassed the 2000 first generation Honda Insight as the all-time EPA-rated most fuel efficient gasoline-powered car available in the U.S. without plug-in capability.In late 2017 Chevy introduced the Chevy ZH2 that runs off of hydrogen fuel cells.