There are some technologies with which you just don't want to be on the cutting edge.

The Honda Civic GX, a car powered by compressed natural gas, is a perfect case in point.

It's a car that is so clean that on heavy smog days the air coming out of the tailpipe is cleaner than the air that went in, according to tests cited by Honda spokesman Chris Naughton.

The technology, the cleanest engine of any tested by the Environmental Protection Agency, is not the only reason to be tempted by the car; the purchase of the car can qualify buyers for a $4,000 tax credit on the $24,000 car; buyers also can purchase a home refueling system that hooks to an existing home natural gas supply and fills the tank overnight as it slowly pressurizes the gas into the car's tank.

But the negatives for buyers outside of New York or California more than outweigh the advantages.

For one, if you don't have all night to fill your tank, you have to find a high-pressure compressed natural gas filling station. That means that trips outside of a 100-mile radius would have to include a stop at a filling station, and they are few and far between. The car has a range of about 200 to 225 miles on a single tank.

For instance, Pittsburgh's closest public fueling station, which does not require a special card key, is at a Uni-Mart in State College, 118 miles away, according to the U.S. Department of Energy's alternative fueling locator system.

The home system costs about $4,000, but buyers can again be eligible for a tax credit. While the cost of the fuel from home amounts to about half that of filling a conventional gasoline car, it would still take about 64,000 miles to pay off the purchase of the home system before the tax credit.

If that doesn't deter a willing buyer, then consider this:

The home refueling system, known as Phill, is produced by FuelMaker Corp., which sells the system through independent agents. The authorized dealer in Pennsylvania is George Collazo of Collazo Contractors, who will hook up the gas pipes and electricity, but, because he is based in Strasberg, Lancaster County, he said he won't come to Pittsburgh to install the system because it is too far.

But if Mr. Collazo or another dealer could be induced to come to Pittsburgh, it would be difficult to have regular maintenance performed on the car. Mr. Naughton said the reason Honda is not marketing the car outside of New York and California is that there aren't dealers outside of those states who are certified to repair a car with a pressurized fuel system. He said Honda had received inquiries from people in Arizona who want to buy the car, but they would not be able to get it serviced.

The company will sell the cars to companies or governments as fleet vehicles, but those fleets have their own refueling systems and mechanics.

Even in the places where the company is selling the cars, they are hard to get.

Berkeley Honda, in Berkeley, Calif., has a waiting list of more than a dozen people who want to buy the car, but the company doesn't expect to get any until March at the earliest, and even then, it is not expecting enough cars to eliminate the list.

So, why would someone wait for the car?

It's clean, even cleaner than a hybrid, because it uses no gasoline. And, it does not depend on foreign oil, because more than 90 percent of the natural gas is produced domestically as anyone living near a well in Monroeville or Oakmont can tell you.

The car has all of the details that make Hondas nice cars. Other than the natural gas, which is provided to the engine with a fuel injector, the car is like other Hondas, with a five-speed automatic transmission, and city/highway fuel economy that is the equivalent of 24/36 miles per gallon of gasoline.

It has air bags for the driver's and passenger's seats and side-curtain air bags and an anti-lock brake system.

Mr. Naughton said the company does not have any immediate plans to market the car outside of California or New York.

"Those are the two areas where we think there is the infrastructure to support it," he said.

So until that changes, the rest of us will be off the waiting list.