As we look for cleaner fuels and cheaper prices, one energy source has a lot of people talking: it's natural gas. Only a fraction of cars use it for fuel, although that might be about to change.

The EPA has called the natural gas Honda Civic GX the cleanest internal-combustion vehicle on Earth. Compared with vehicles that use conventional diesel and gasoline, natural gas vehicles put out significantly fewer pollutants and harmful greenhouse gases.

Most natural gas used in the United States is produced right here in America, and it's less expensive than gasoline. But as demand increases, we can probably expect to see natural gas stations popping up more and more.

What about safety? The natural gas tanks are made of half-inch thick steel and are often wrapped in protective reinforced fiberglass. They're actually more rugged and durable than traditional gasoline tanks.

While you might not be rushing out to buy a natural gas car just yet, it's another alternative fuel choice that will help reduce greenhouse gasses, and save money at the pump.