Of the top 10 fuel efficient vehicles made in 1984 to the present, half are available for sale in the 2012 model year, according to the latest ratings on https://www.fueleconomy.gov, a website developed and maintained by Oak Ridge National Laboratory for the Department of Energy and Environmental Protection Agency. The Chevrolet Volt takes the top spot with 58 miles per gallon in the city and 62 mpg on the highway. "New high technology vehicles are replacing older low-technology vehicles," said Bo Saulsbury of ORNL's National Transportation Research Center. "The auto industry is making headway in vehicle technology, which gives people more fuel efficient options." There's also a best fuel economy list that rates the top 10 all-electric vehicles (1984 to present) and one that rates the top 10 2012 model year vehicles.