Greenwire: U.S. EPA today unveiled proposed regulations that would tighten fuel efficiency standards to significantly cut carbon emissions from tractor-trailer rigs and other heavy- and medium-duty vehicles by 2027.
When fully phased in by that point, the new standards would cut greenhouse gas emissions and fuel consumption by up to 24 percent, the agency said in a news release this morning, and would reduce carbon pollution by 1 billion metric tons over the life span of vehicles sold under the program....