America's current crop of hybrid vehicles have gained increasing prominence in the nationwide energy debate, but they aren't the only options available. In Europe, where gas prices hover around $6 a gallon, the quest for fuel efficiency takes on a more fevered pitch. Across the pond, the diesel engine is proving to be the most popular option for improving gas mileage.
Americans tend to associate diesel with loud engines clattering their way down the road, spewing clouds of exhaust as they go. In reality, diesel engines can be just as quiet as their gasoline counterparts. And while diesel particulate and nitrogen oxide emissions are higher than gasoline's, diesels are 30 to 60 percent more efficient in fuel use and produce fewer greenhouse gases. Most diesel engines can also easily be converted to run on biodiesel, fuel made from vegetable oil.
The purely electric car lost favor nearly a century ago and has yet to return successfully. Today, demand for electric cars remains tempered by their limited 100-mile range and lack of power. However, some hybrid models can be altered to become plug-in optional, allowing the owner to charge the car from an outlet and forgo the use of gas for short periods of time. Such a system allows the car to drive about 50 miles on battery power before automatically switching back to gasoline.
Finally, there is the much-hyped, but still unavailable, fuel cell. Powered by hydrogen gas (usually cultivated from petrochemicals), fuel cells can provide more energy than gasoline engines. Popular with the White House, fuel cell cars have become the Holy Grail for engineers, and many leading car manufacturers promise to be the first to mass-market such a vehicle. But most researchers don't see them as a viable option for at least 10 years. In a recent issue of Science magazine, researchers David Keith and Alexander Farrell noted that fuel cell technology is likely to be based initially on petroleum hydrocarbons. As a result, it would be just as effective and far cheaper to simply encourage energy-saving technologies to hold on to those hydrocarbons for the future.
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Green Car Journal
A quarterly consumer magazine focusing on, well, greener cars.
Union of Concerned Scientists' new hybrid consumer information site.
The Environmental Protection Agency's fuel economy site, which allows you to make side-by-side comparisons of any make or model, including both mileage and smog and carbon emissions.
Thoughtful weblog for more technical news about developments in green transport, from biofuels to hybrids to electric vehicles.
A retrofit option for hybrids that allows you to plug in your car overnight, making your engine effectively gas-optional for short trips. Currently available on a demonstration basis only.
Encyclopedic Web site chock full of useful information, including overviews of hybrid cars and biodiesel, with instructions for converting a diesel engine from fossil fuels to veggie oil.