Read the full story in the New York Times.
Automakers have steadily improved the fuel economy of new cars, S.U.V.s and pickup trucks, pushed by federal regulations. While some companies have introduced hybrid and electric cars, most of the recent gains have come from improving traditional gasoline-powered vehicles.
The Trump administration is now proposing to weaken those Obama-era vehicle rules after 2021. A big question is whether automakers can meet increasingly strict standards in the years ahead. To put this debate in context, here’s a look at how automakers have improved the fuel economy of some of their most popular models so far — and what the future might hold.