Hybrids may be the rage when it comes to mass-producing fuel-efficient cars, but there are still a lot of other alternatives. Tax incentives exist for people who purchase alternative-fuel cars.

Electric Cars

There's an ongoing debate about whether the electric car is really dead. After being promoted in the late 1990s, cars running strictly on electricity have been steered off the road and onto golf courses and tourist destinations.

Electric cars rely on batteries to provide electricity to an electric motor. The cars produce almost no pollution. However, many are charged from electricity produced from coal, which does produce pollution at the power plant where emissions can be heavily controlled and regulated. Electric cars have a range of only 50 to 100 miles and aren't known for their gusto. While this may limit long trips on busy roads, it can be a perfect fit for short trips on residential roads or places where speed isn't of the essence, but cleaner air is.

Many cities and even amusement parks use electric buses or shuttles for moving people around. Because buses work on set times and routes, the time needed to charge them is incorporated into their routine schedules.

Low-speed electric vehicles (LSVs) are gaining popularity in some planned neighborhoods, college and business campuses, and even tourist locations. In Key West, Florida, electric cars are available for rent alongside scooters. These cars allow families and groups to get around without adding noise and exhaust to the downtown air.

Flex-Fuel Vehicles

Flexible-fuel vehicles, or FFVs, are made to run on a mixture of gaso-line and an alternate fuel such as ethanol or methanol. Standard gasoline engines can't operate using flex fuels, but FFVs can burn both — and that's what makes them so flexible. There are a variety of FFVs on the market, including sedans, trucks, and sport utility vehicles.

Ethanol — otherwise known as ethyl alcohol, grain alcohol, or moon-shine — leads the way in replacing a portion of the gasoline. It's made by distilling a fermented brew of corn, yeast, sugar, and water. Other plants, such as switchgrass, are being considered as corn substitutes. It takes one bushel of corn to produce two and a half gallons of ethanol. There is concern that the environmental impact from growing plants to produce ethanol (i.e., from the use of fertilizers, pesticides, and transporting plants to processing facilities) outweighs the benefits of burning cleaner fuels.

The most common mixtures using ethanol are E10 and E85, where the number accounts for the percentage of ethanol in the mixture compared to gasoline. Gasoline is still needed because ethanol isn't volatile enough to ignite. E10, comprised of 10 percent ethanol, is used more for an octane enhancer, while E85 is considered a full-fledged alternative fuel. Ethanol burns cleaner, significantly reducing emissions.

There are a variety of ethanol-fueled cars available; Ford and General Motors are the major manufacturers. Ford offers the Crown Victoria, Mercury Grand Marquis, Lincoln Town Car, and F-150 pickup truck in E85 options. GM offers Suburbans and Yukons, along with a Chevy Police Tahoe. Because fueling stations are limited, FFVs can be better suited for public and private fleets where E85 can be supplied at a set location.

A less-popular fuel alternative is methanol or wood alcohol, which is made primarily from natural gas or methane. M85, the most common methanol additive, must be stored either as a compressed gas or a liquid. Significant amounts of electricity are needed to compress and liquefy the gas. Methanol had its day back in the late 1980s and 1990s when California led the charge in using this alternative fuel, although it was never really embraced by the country.

Alternative Fuel Vehicles

Where FFVs rely on ethanol and methanol as a fuel component, alternative fuel vehicles (AFVs) rely on a combination of gasoline and either com-pressed natural gas (CNG) or liquefied petroleum gas (LPG). As with other alternatives, fueling station locations are spotty across the United States. Most AFVs on the road were converted from standard gasoline-powered engines. Tax incentives encourage companies to convert their fleets and private individuals to convert their personal cars. Some states even allow drivers of certified AFVs to use high-occupancy lanes.