If you’ve watched any cable news or read the editorial pages of a major newspaper in the past few months, you’re likely to have come across advertisements for the Pickens Plan. Devised by legendary energy baron, T. Boone Pickens, the Pickens Plan promises to decrease America’s foreign oil expenditure by more than 40 percent. One element of the plan is the promotion of a long existent but relatively unused automotive technology: engines powered by compressed natural gas.

While CNG vehicles aren’t the linchpin of the Pickens Plan, it’s interesting that such an obscure technology would factor in at all, especially considering all of the excitement about the new wave of electric and hybrid-electric vehicles that are expected to hit the market in the coming years.

The answer may lie in fact that Pickens owns the largest provider of natural gas for transportation in the United States, Clean Energy Fuels. Or perhaps it’s the $160 million joint investment he and the Perseus investment group entered into earlier this year to develop a mass-market CNG powered car. Or maybe both of these investments arose out of a genuine interest in environmental responsibility and a reduction of America’s dependence on foreign oil?

As with most of the green capitalist endeavors to hit the financial pages in recent years, the success of the Pickens plan and of natural gas vehicles in general will be determined not by intentions, but by technological feasibility and market acceptance.

Although CNG has enjoyed some success abroad, there are very few regions within the United States with enough filling stations open to the public to facilitate widespread use. Italy and Canada boast the most CNG-friendly infrastructures, and countries all over Europe, South America, Asia, and the Middle East, have converted their public fleets to the fuel. Several states and municipalities within the US have even converted their fleets to run on natural gas, but the fact remains that the technology is far from even gaining a foothold with car buyers. Except in Utah.

As recently covered in The New York Times, the popularity of CNG powered vehicles in Utah has skyrocketed in the past year due to rising gas prices and the widespread availability of filling stations offering the fuel. More than 6,000 CNG vehicles currently exist in Utah, and that number is growing by several hundred each month.

Since compressed natural gas emits about 15 percent less greenhouse gases than gasoline, and is significantly less expensive—although the gallon of gas equivalent can be tricky to calculate—its newfound popularity is understandable. But how likely is this trend to spread elsewhere?

Aside from the scarcity of fueling stations in most parts of the country—which isn’t quite as problematic as one might think given that a full tank can usually take you about 200 miles—there’s also a shortage of legally approved CNG-burning cars on the market. The only major model available in he United States is the Honda Civic GX. The GX is only available in select states, and according to the Times article, about a quarter of 800 that have been sold so far this year were sold in Utah.

The Civic GX boasts a few advantages beyond fuel efficiency and its certification as an Advanced Technology Partial Zero-Emission Vehicle. Because gas burns cleaner than liquid fuel, maintenance costs on the GX run considerably lower than those of gasoline vehicles. Oil changes are only required once per 10,000 miles, and tune-ups once every 100,000. The engines are also reported to last more than 500,000 miles with good maintenance, though verification for this claim is difficult to come by. The Civic GX has a sticker price of around $25,100.

Because the availability of new and used Civic GXs has been so limited in markets where the technology is rising in popularity, many drivers are choosing to convert their gasoline powered cars to run on CNG. This can be problematic because of strict conversion standards in many states and inspection and certification costs, which can be quite pricey. The cost of the conversions vary greatly depending on what model of vehicle you start with—some cars will run you less than $10,000, while others can cost several times as much.

But there are factors beyond the scarcity of Civic GXs and the cost of conversion that threaten to keep CNG vehicles from breaking into the mainstream. For one, if the GX is any indication, these cars are likely to remain more expensive than their hybrid counterparts, even though their emissions are higher and the fuel savings they offer are relatively nil compared to hybrids. The Civic GX is $2,000 more expensive than a Civic hybrid, and $7,000 more expensive than a standard Civic.

Furthermore, many detractors point out that developing new cars to run on CNG just distracts from the real challenge facing carmakers and society at large: getting off of fossil fuels and on to renewable energy.