2000 Honda Civic GX

You can't always spot them in a crowd, but alternative-fuel vehicles are among us.

If you're in New York, it may be a natural gas Ford Crown Victoria taxi that's dropping you off at La Guardia. In Minneapolis, the carpool in the next lane could be traveling in an ethanol-powered Dodge Caravan. And that just may be an electric Chevrolet S-10 pickup offloading construction materials in your Phoenix suburb.

The fact is, unless an alternative-fuel vehicle sports graphics designed to draw attention to its clean-fuel nature, you'd never be able to tell it from its gasoline-fueled peers. That's how it is with the many Honda Civic GX natural gas sedans being used to conduct city business in Long Beach, California, and other municipalities nationwide and the electric Nissan Altra EV minivans transporting utility executives in San Diego.

In all these cases, such cars, trucks, and vans go about their business just like the conventional vehicles that surround them on the highway, with one notable exception: They never stop to fill up with gasoline.

Alternative fuels have made considerable inroads on the automotive scene in recent years. Whether electric, methanol, ethanol, natural gas, propane, or biodiesel, there are vehicles built to run on these fuels and drivers putting miles on them every day.

There's good reason for this. For the most part, these vehicles drive just like their gasoline-fueled counterparts. The performance of a flexible-fuel Dodge Caravan running on renewable ethanol fuel is nearly indistinguishable from when this model is running on gasoline. The same goes for GM's Sierra pickup when it's running on natural gas or gasoline, or Ford's Econoline when it's running on gasoline or propane.

What was once considered a novelty by auto enthusiasts now appears a likely part of our motoring future. All you have to do is follow the news: Natural-gas vehicles such as the Civic GX and Crown Victoria are being built on the assembly line alongside gasoline models. Flexible-fuel minivans and pickups that run on either corn-derived E85 ethanol or gasoline are being sold in many states. Four electric vehicle models are being leased or sold to consumers and fleets in specific test markets, primarily California and Arizona. Two electric pickups are aimed primarily at fleets nationwide. Hybrid electric vehicles will begin hitting American highways this fall.

As exciting as all this is, even more advanced clean-fuel technologies are coming. DaimlerChrysler, Ford, and Ballard Power Systems are involved in a near-billion-dollar development program that will find vehicles powered by hydrogen fuel cells. Other automakers, General Motors, Honda, and Nissan among them, are actively pursuing fuel cell development with the goal of bringing these vehicles to the market in the next five years.

The promise held by these vehicles is significant: Hydrogen fuel cell vehicles electrochemically create the electricity to power a vehicle's electric-drive motors. The process takes place without combustion, hence no nonmethane organic gas byproducts and no greenhouse gas emissions. The only byproducts are heat and water vapor. Some emissions are created if the hydrogen to power these fuel cells is reformed from other fuels like methanol or natural gas, but the levels are still much lower than those produced by even the cleanest-running cars today.

There's no doubt clean-fuel vehicles are coming to the mass market. The question is which will make their mark first, and when. In the meantime, gasoline-fueled internal-combustion engines will continue to run increasingly cleaner, allowing automakers to meet stringent state and federal regulations and to differentiate their products on the market.