New California Cars Display Smog, Global Warming Scores

The label will show a simple ranking system that provides consumers with practical information that can help them choose the most environmentally friendly vehicle that still meets their transportation needs.

"This label will arm consumers with the information they need to choose a vehicle that saves gas, reduces greenhouse gas emissions and helps fight smog all at once," said California Air Resources Board Chairman Mary Nichols. "Consumer choice is an especially powerful tool in our fight against climate change."

The environmental performance label will have two scores on a scale of 1-10, a global warming score and a smog score.

The higher the score the more environmentally friendly the car is. The average new car will score five on both scales.

Electric cars earn the highest ratings on both scores. One car rating 10 on both scores is the GEM electric car from Global Electric Motors, a Chrysler company. Priced at $12,495, the GEM is 100 percent battery-electric and does not use any gasoline.

A GEM electric car is the highest rated car for both the smog and the global warming scores. (Photo courtesy Global Electric Motors)

Greenhouse gases trap heat in the atmosphere, creating global warming. Scientists are certain that human activities such as burning gasoline for transportation are changing the composition of the atmosphere and warming the planet's climate.

Greenhouse gases emitted from vehicles include carbon dioxide, CO2, methane, nitrous oxide, and hydroflurocarbons from air conditioner refrigerant. Greenhouse gas emissions are identified as the CO2-equivalent value.

The California global warming score is based on the sum of a vehicle's greenhouse gas emissions, which are identified as the CO2-equivalent value.

The global warming score ranks each vehicle's CO2-equivalent value on a scale of one to 10 relative to all other vehicles within the current model year.

A score of 10 is the cleanest a vehicle can rate and indicates that the vehicle emits less than 200 grams of CO2-equivalent per mile driven.

A score of one is the dirtiest a vehicle can rate and indicates that the vehicle emits more than 520 grams of CO2-equivalent per mile driven.

The global warming scores are adjusted to reflect the contribution of greenhouse gas emissions from the production and distribution of the fuel used to power the vehicle.

Smog is hazy air pollution produced by the photochemical reaction of sunlight with volatile organic compounds and oxides of nitrogen released into the atmosphere, especially by automobile operation.

California's new smog score ranks each vehicle's pollutant levels of non-methane organic gases and oxides of nitrogen relative to all other vehicles within the current model year.

Smog scores will be on a scale of one to 10, with 10 being the cleanest. The average vehicle available in California today will get a smog score of 5. Many pre-2004 vehicles fall below a smog score of one. This is because, over time, there have been significant advances in air pollution control technologies and the Air Resources Board has established more stringent pollution standards for vehicles.

For a list of the top 10 cleanest cars, click here to go to the California Air Resources Board's consumer website.

Copyright Environment News Service (ENS) 2009. All rights reserved.