The American Automobile Manufacturers Assn. (AAMA) and the Association of International Automobile Manufacturers (AIAM) have petitioned the U.S. Environmental Protection Agency (EPA) to establish national year-round limits on the concentration of sulfur in unleaded gasoline.
Sulfur interferes with catalyst technology on current and future vehicles, and has the effect of increasing air pollution from these vehicles. AAMA and AIAM have called for sulfur limits that are as low as practicable, but in no case greater than 40 ppm by weight, or not greater than 30 ppm by weight annual average, with a per gallon cap of 80 ppm. These benchmarks are consistent with the sulfur limits currently enforced in California, the state with the strictest emissions rules.
In addition to low sulfur, other gasoline improvements are also critical to more clean air benefits. Some of these issues will be the subject of further auto industry regulatory initiatives.
AAMA President and CEO Andrew H. Card and AIAM President and CEO Philip A. Hutchinson agree that automakers have made tremendous strides in reducing vehicle emissions. "Today's vehicles are 96% cleaner than those of the 1960s, and Low Emission Vehicles will be 99% clean," says Card. "But fuel quality is lagging behind the state-of-the-art vehicle technology. Cleaner vehicles will maximize their potential only when they operate on clean fuels."