Study Says Vehicle Age-Pollution Link Untrue
A team of researchers measured emissions from 60,000 motor vehicles in California, concluding that a large portion of newer models polluted more than older cars. The difference was maintenance -- poorly maintained new cars produced more pollutants than well-maintained older ones. U.S. Environmental Protection Agency emission standards are based on computer models that assume that older cars are more polluting than newer ones, and treats all cars from a specific model year as generating the same level of pollution. In the study, only 7% of vehicles produced 50% of carbon monoxide emissions, while 10% accounted for half of hydrocarbon pollution. These "gross polluters" included vehicles both old and new. The emission levels from 40% of the oldest models were lower than those produced by 20% of the newest cars in the study. The researchers urge EPA to adjust its pollution models and emphasize maintenance over vehicle age. The study findings can be found in the current issue of Science magazine. The findings appear to undermine assumptions that vehicle fleet replacement will automatically lead to air pollution reduction. They would also seem to strengthen arguments in favor of enhanced vehicle inspection and maintenance programs and render unfair any notion of a smog fee levied on the basis of a generic "blue book" emission rating. Wall Street Journal
