CNG-powered cars only have a maximum driving range of about 170 miles (273 km) before needing to refuel, making the small number of CNG fueling stations across the United States -- roughly 1,600 stations, and not all of them open to the public -- hard to rely on. Some regions are better served than others, such as California, Utah and New York, but get into the heartland and may you find yourself out of luck.
With Phill installed at home, a CNG-powered car owner can expect to save money at the tank as well as help save greenhouse gas emissions -- all while never having to wait in line for a fill up. CNG sells for about 50-cents-a-gallon-equivalent less than gasoline from a public station. With an HRA, owners save even more: By hooking directly into the residential natural gas line, CNG typically costs around $1 a gallon (of course, costs depend on your local natural gas company's pricing).
Phill's built to last, too. It requires virtually no maintenance and is good for an estimated 6,000 hours of operation, after which it can be remanufactured up to three times (giving it a total life of 24,000 hours of use).
And though it doesn't bring our dependence upon fossil fuels to an end, fueling up with CNG offers reduced emissions when compared with gasoline. According to the U.S. Environmental Protection Agency (EPA), CNG-powered vehicles reduce carbon-monoxide emissions by 90 to 97 percent, nitrogen-oxide emissions by 35 to 60 percent and carbon dioxide emissions by 25 percent when compared to conventional gasoline-powered vehicles. They also generate less air pollution because they produce fewer toxic emissions, including little to no particulates [source: NaturalGas.org].