The U.S. Department of Energy’s Alternative Fuels Data Center’s October 2014 Alternative Fuel Price Report illustrates the relative price stability of CNG compared with prices of other transportation fuels. Looking at the AFDC price trends chart showing the trend in prices paid at the pump for different sources of transportation fuels, we can make two observations regarding the price of CNG. CNG prices are more stable over time and the price is consistently lower than that of other fuels with the exception of electricity.
"Fuel Prices." Alternative Fuels Data Center:. U.S. Department of Energy, 1 Oct. 2014. Web. 10 Apr. 2015. http://www.afdc.energy.gov/fuels/prices.html.