U.S. Wants Report Card for Cars System Would Rate Fuel Economy, Emissions; Industry Says Government Veers Into Issuing Opinions By JOSH MITCHELL WASHINGTON—The government proposed labeling each new passenger vehicle with a letter grade from A to D based on its fuel efficiency and emissions, part of a broader effort by the Obama administration to promote electric cars and other advanced-technology vehicles. Journal Community The proposed new rules, released jointly Monday by the Environmental Protection Agency and the Transportation Department, would be the most substantial change in 30 years to the familiar price-and-mileage labels affixed to the windows of new...