Wards Intelligence’s Fuel Economy Index shows the average fuel economy of light vehicles sold in the U.S. in the first quarter of 2018 was 25.8 mpg (9.1 L/100 km), up 1.1% from same-period year-ago. National average gasoline prices continued to rise in terms of month-to-month and year-over-year. The increases were not enough to push drivers to alternative powertrains to any major extent. Electric and plug-in hybrid vehicles showed incremental gains, while hybrids took a small downturn ...