"Coming Soon: U.S. Tier 3 Emissions and Fuel Standards"
"WASHINGTON, DC -- Sometime before the end of March, the U.S. Environmental Protection Agency is expected to propose new national vehicle emissions and fuel standards by updating a program called Tier 3. Updated Tier 3 standards would cut smog and soot, among other pollutants, by establishing new standards for light-duty vehicles and their fuels to reduce emissions of the most toxic pollutants."
The standards in this rule are expected to lead to reductions in ozone, particulate matter, nitrogen dioxide, and mobile source air toxics and impose new restrictions on the sulfur content of gasoline."Source: ENS, 03/25/2013