In 2007 you can expect to see more and more manufacturers offering diesel cars, including luxury models from the likes of Mercedes.
For a map of biodiesel stations:
Particulate matter and smog: Even though biodiesel cars emit less CO2, they still put out some nasty particles and pollutants. Current manufacturers of biodiesel are desperately researching for additives that will make biodiesel even cleaner.
Limited SUV choices: If you are interested in an SUV or a truck, the diesel options are heavy on the big models and light on the small to midsize options. Currently, the only small SUV is the Jeep Liberty. There are no fuel-efficient options for diesel trucks. The big trucks and SUVs are models like the Ford Expedition, the Dodge 2500, the Chevy Silverado and the Hummer H1.
Price: The price of biodiesel in combination with these fuel-guzzling trucks can make this alternative fuel price prohibitive.
Cold weather: Be aware of cold weather viscosity problems with all diesels. The higher the vegetable oil content of the biodiesel you use, the more viscous the fuel becomes in cold weather.
For the past three years, I have been an earth warrior. Well, not exactly. When I commuted across the Bay Bridge into San Francisco, the 14-mile trip could take an hour each way. I noticed all the carpools whizzing by me avoiding the traffic and sailing into the city. My schedule was too erratic for a regular carpool, so I started researching the alternative-fuel vehicles that get access to the high-occupancy vehicle lanes in California, even when there's only one person in the car. At the time, hybrids did not get this special access, so I purchased a natural gas car.
Why Natural Gas?
Natural gas is a cleaner-burning fuel -- score one for the environment. But natural gas is still a fossil fuel. The good news is that most natural gas used in the United States comes from within our borders (including offshore drilling) or from Mexico. The bad news is that the quest for more natural gas is one of the biggest incentives for oil companies to lobby for the opening of the Arctic National Wildlife Refuge. As the driver of a natural gas vehicle, my motto of compromise was "I may be riding with ANWR, but at least I'm not riding with Saddam."
Fuel prices: The cost of CNG (compressed natural gas) is traditionally cheaper than regular gas. That's why so many fleet vehicles are run off CNG.
Clean burning/longevity: The cars last longer than traditional gasoline vehicles because the engine burns so clean.
HOV access: Carpool access in California and Arizona.
Vehicle selection limited: The lack of options when buying a CNG vehicle. Honda makes a natural gas Civic, Chevrolet makes a few CNG trucks, Ford offers vans and a pickup truck (the F-150).
Reduced range: Because natural gas has twice the volume of gas (it takes up twice the space of its liquid, gasoline equivalent), a tank of CNG will not take you as far as a tank of gas.
Refueling stations sparse: Adding to the refueling woes, finding a natural gas station can be difficult. It was fine for me when I was commuting because I stuck to the same route every day. But natural gas cars are not for road trips; you'd zigzag your way to your destination going from one obscure CNG fueling station to the next, praying you didn't run out of gas.