Since the 1970s, automakers selling cars in the United States have published EPA certified fuel efficiency numbers on the window sticker of all new cars. For 2009, new car buyers in California will get a new sticker to contend with on their cars. The California Air Resources Board has mandated a new sticker that gives each car a 1-10 rating for smog related emissions and greenhouse gas emissions. Cars sold in California have already had a smog index label for a decade. The new sticker adds greenhouse gases with both scores being calculated based on data provided by manufacturers to the EPA. Average cars will get a rating of five with cleaner cars such as the Honda Civic hybrid or Prius getting a 9 while thirstier vehicles get lower scores. All new vehicles sold in California after Jan, 1 2009 will need the new label although 2009 models appearing soon are expected to start carrying it.