While automakers work to lower vehicle emissions, the Environmental Protection Agency (EPA) is turning its attention to the fuel that powers those cars.
The EPA will introduce a new rule to reduce sulfur in gasoline by two-thirds starting in 2017, according to The Detroit News.
The new "Tier 3" rule calls for a reduction in sulfur from 30 parts per million to 10 ppm, bringing U.S. standards in line with those of the European Union, Japan, and South Korea.
It will also bring U.S. gasoline blends in line with those already sold in California, which capped sulfur in gasoline at 10 ppm as of September 2006.
The agency says the new rules will result in an 80-percent reduction in smog-forming gases from light-duty cars and trucks, and a 60-percent reduction from heavy-duty vehicles.
Rush hour traffic in Washington, D.C. (photo by Flickr user haddensavix)
That amount is also significantly less than what the American Petroleum Institute--the oil industry's main lobbying group--estimated.
In October, the institute claimed capital costs related to the production of low-sulfur gasoline would add 6 to 9 cents per gallon to the cost of gasoline.
While the oil industry appears less than enthusiastic about the new standards, carmakers are apparently on board.
Last year the Alliance of Automobile Manufacturers--a lobbying group that represents several major automakers--got behind the EPA's plan.
The group said low-sulfur gasoline would cut vehicle emissions without requiring manufacturers to make modifications, since they are already building cars to those standards outside North America.
The EPA last cut sulfur levels in gasoline in 2000, when it mandated that they be lowered from an average of 300 ppm to the current 30 ppm.
The agency also phased in "Ultra Low Sulfur Diesel" fuel between 2006 and 2010, to allow a new generation of exhaust aftertreatment systems to work properly.
All new diesel cars and trucks sold in the U.S. are required to use this fuel, which has a sulfur level of no more than 15 ppm.