You haven't refueled in two days, yet you've logged 500 miles on your rental car doing sales calls in California. Everyone else is stopped in yet another traffic jam, but you are driving along at a modest speed in the carpool lane, without another passenger. Yet you aren't worried about running out of gas or getting a citation. Sound like the impossible dream? No, all you did was think environmentally conscious and rent a hybrid.

With all the environmental benefits of being eco-friendly, more travelers are also opting to rent environmentally friendly vehicles. Unfortunately, the task isn't as easy as picking up the phone or booking online, and may dip more toward the impossible dream.

What are they?

The options are natural gas, electric and hybrid. Each vehicle uses different forms of fuel but all have the same underlying feature: eco-friendly.

Besides the environmental benefits, renting a hybrid gas/electric car can be gentle on your wallet. One tank of gas gets you up to 55-60 miles-per-gallon and 700 miles per tank. Although it's electric, its battery pack recharges automatically, using no gas when driving at slow speeds. Plus California law allows drivers of hybrid vehicles to use the carpool lane, even if driving alone, although it can seat up to five passengers.

Natural gas vehicles nets 30 miles per gallon, although natural gas is less expensive than gasoline. There are more than 200 natural gas refueling stations in Arizona, California, and Nevada. (You can do your homework by checking at www.cleancarmaps.com to get a current list of refueling stations.)

Additional benefits to renting a natural gas vehicle--not only can you return the vehicle empty at no additional charge but these vehicles are eligible to travel in the car pool lanes with only one person. This is a big plus in southern California.

To find which vehicles qualify for this status, check out the EPA's green vehicle guide.This guide identifies the lowest emitting and most fuel efficient vehicles with a "SmartWay" designation, providing a quick

Where to rent them?

Unfortunately, auto rental agencies are behind the eight-ball on the demand of these hybrid vehicles. In general, hybrid cars are more difficult to find, and many agencies don't offer them at all - at least not yet. However, in the next few years, based on the demand, the production will increase, and the rental selections should improve.

If this hasn't discouraged you from seeking energy-efficient vehicles, check out EV Rental Cars. Debuting in 1998, it is the first and only rental company in the United States to exclusively offer a fleet of all-environmental hybrid-electric vehicles, with more than 350 cars at 8 locations throughout the country. EV Rentals has its largest presence in California, and those locations include: LAX, San Diego, Santa Ana, San Francisco, San Jose, Oakland, Phoenix, and Las Vegas (the latter temporarily closed). The company has prevented more than 100 tons of air pollution and passed on to its customers more than $1 million in fuel costs savings by acting environmentally.

EV rents two types of environmental vehicles--hybrid gas/electric and natural gas. For example, a midsize hybrid from EV might be a Honda Civic; full-size Toyota Prius; and SUV Highlander Hybrid. Rates are affordable, ranging from $25 for midsize up to $60 for SUV per day.

Last year, Enterprise Rent-A-Car announced their efforts toward sustainability by reducing fuel consumption and related emissions, although its available 4,000 hybrids (out of 1.1 million total rentals) are still limited to certain areas. Other rental giants, like Hertz and Avis, also say they're slowly building their environmentally-friendly fleet.

Since the demand is higher than the stock, your best bet is to get in line first and book yours early. The demand and supply chain also gives rental agencies the go-ahead to charge premium rates, so be prepared to pay slightly more to be green. If "green" rentals are not available, you can still be environmentally friendly by selecting the cleanest available, a more fuel efficient vehicle, and refuel wisely, either early in the morning or late in the evening, to reduce evaporative emissions.

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