Ford Motor Co. is adding to alternative fuel vehicle offerings with compressed natural gas and liquefied petroleum gas options for the 2014 F-150 pickup truck. Ford will become the first automaker this fall to offer both a CNG and propane autogas version of a half-ton pickup. Ford expects to sell about 15,000 CNG-LPG vehicles this year. Chrysler and General Motors are offering bi-fuel trucks that can be powered by either CNG or gasoline.