Find the green car that is just right

Looking to reduce your carbon footprint? Your car is an obvious place to start. While standard, gas-fueled cars dominate the roads, there are a few current alternatives and some promising future technologies.

Partial Zero Emissions Vehicle and Super Low Emissions Vehicle are emissions ratings from the California Air Resources Board, which has strict regulations on vehicle emissions, classifying cars in a system that ranges from Low Emission Vehicle to Zero Emission Vehicle. Several states, including New York, Massachusetts, Connecticut, Vermont, Rhode Island, Maine, and New Jersey use the CARB emissions classifications, accounting for a large portion of cars sold in the United States. (Florida is in the process of implementing the CARB rules.)

Some hybrids qualify as Advanced Technology Partial Zero Emissions Vehicles because of their very low emissions and electric powertrains under CARB rules, but plenty of standard gas engine cars with similarly low emissions levels qualify as PZEVs and SULEVs. PZEV, SULEV, and AT-PZEV classified cars release only one pound of hydrocarbons into the atmosphere over 100,000 miles of driving. AT-PVEVs and PZEVs restrict pollution even more by emitting zero evaporative emissions. PZEV and SULEV-rated cars are almost as clean as hybrid AT-PZEVs, and usually less expensive.

While SULEV and PZEV cars limit the kinds of pollutants that lead to smog and all of its attendant health problems, they don't restrict carbon dioxide, a greenhouse gas. As carbon dioxide production relates directly to the amount of gas burned, higher mileage cars, such as hybrids, release less carbon dioxide. Also, cars that earn a SULEV or PZEV rating may be sold with different emissions systems in non-CARB states. The non-CARB versions will only meet Federal requirements, which aren't nearly as strict.

PZEV-rated car

Volkswagen Jetta

SULEV-rated car

Ford Focus

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