Compressed natural gas burns cleaner than gasoline or ethanol, resulting in lower greenhouse-gas emissions, but it does not provide a fuel economy boost over gasoline. Pike Research reports annual global sales of CNG-propelled vehicles will jump 68 percent to about 3.2 million vehicles in 2016 from about 1.9 million last year. U.S. annual CNG sales are estimated to almost quadruple to 33,000 vehicles in 2016 from about 8,400 in 2012. As of Sept. 1, there were 901 CNG stations and 45 liquefied natural gas (LNG) stations in the U.S., compared to about 2,600 propane stations. The Honda Civic CG, named the greenest vehicle sold in the U.S., is the only production CNG-powered car in the country.