Log in | Subscribe | RSS feed

What’s New

US EPA proposes new heavy-duty diesel emission standards and low sulfur diesel fuel legislation

17 May 2000

At a press conference held today in Washington, DC, the US EPA Administrator Browner announced proposed emission standards for new heavy duty truck and bus engines and new diesel fuel sulfur legislation. Since last September, when the EPA first unveiled its plans for the new rules, this proposal has been subject of intense lobbying by environmental groups and the petroleum and diesel industry.

The proposed fuel regulation limits the sulfur content in diesel fuel to 15 ppm (wt.), down from today's 500 ppm. The fuel provisions would go into effect in June, 2006 to provide a clean diesel fuel in time for implementation of the light-duty Tier 2 standards adopted last December. The proposal discusses various phase-in approaches for the diesel fuel industry to facilitate the complete transition to new diesel fuel at a minimum cost penalty. EPA is seeking comments in its proposal on ways to incorporate additional flexibility for small oil refiners.

Second part of the proposal introduces new, very stringent emission standards for heavy duty highway engines. Ultra low sulfur diesel fuels are being proposed as a “technology enabler” to pave the way for advanced, sulfur-intolerant exhaust emission control technologies, such as diesel particulate filters and deNOx catalysts, which are expected to be necessary to meet the new emission standards. To date, most diesel trucks and buses have not used pollution control devices such as catalytic converters, similar to the devices that have been used on cars for the last 25 years.

The EPA is proposing a particulate matter (PM) emission standard for new heavy-duty engines of 0.01 g/bhp-hr, to take full effect in the 2007 heavy-duty engine (HDE) model year. The proposed standards for oxides of nitrogen (NOx) and nonmethane hydrocarbons (NMHC) are 0.20 g/bhp-hr and 0.14 g/bhp-hr, respectively. These NOx and NMHC standards would be phased in together between 2007 and 2010, for diesel engines. The phase-in would be on a percent-of-sales basis: 25% in 2007, 50% in 2008, 75% in 2009, and 100% in 2010. Gasoline fueled heavy-duty engines would be also subject to these standards, effective 2007. The EPA is also proposing formaldehyde emission standards and new requirements for crankcase emissions control on turbocharged diesel engines.

For comparison, today's PM standard is 0.1 g/bhp-hr for truck engines and 0.05 g/bhp-hr for urban buses. Today's standards for NOx and NMHC are 4.0 g/bhp-hr and 1.3 g/bhp-hr, respectively, and the year 2004 combined NOx + NMHC standard is 2.4 g/bhp-hr.

The EPA estimates that this proposal, once fully implemented, would reduce 2.8 million tons of smog-causing nitrogen oxides emissions per year. Emissions of soot would be reduced by 110,000 tons each year.

According to EPA estimates, the program would cause an average cost increase of about $1000 to $1600 per new vehicle, depending on the vehicle size. The overall cost associated with lowering the sulfur cap from 500 ppm to the proposed 15 ppm level is estimated at 3-4 cents per gallon, comprised of an approximately 4 cents per gallon increased cost to produce and distribute the fuel, and a cost offset of about 1 cent per gallon or more from the vehicle maintenance savings that result from the use of the cleaner fuel.

Public hearings on the proposed regulations will be held in Los Angeles, Denver, New York City, Chicago, and Atlanta approximately three weeks after publication of the proposed rule in the Federal Register. The proposed rule can be downloaded from the EPA website at http://www.epa.gov/otaq/diesel.htm#hd2007.

Source: US EPA