Natural gas prices are dependent on crude oil prices, which have recently increased a lot. The demand is based on weather, growth, competition in the fuel market, storage and exports. In December 201, the prices in the USA were: the imports price 3.65, by pipeline 3.48, and as liquefied natural gas 5.45. The export price was 4.11, by pipeline 3.76 and as liquefied natural gas 12.84. Residential price was at the rate of 9.69, the commercial one 8.28, the industrial price 4.47 and the electrical power 4.15. Considering that natural gas prices are higher than before, the natural gas vehicles market has also increased progressively.