為應對全球氣候變暖，美國環(huán)保總署出臺了相關氣體排放標準，對相應產品供應商提供出了嚴格的要排放標準。 2000年11月21日，美國國家環(huán)保總局發(fā)布了2007年及以后重型交通引擎的排放標準。該條例包括兩點：1 排放標準 2 柴油燃燒規(guī)則 第一部分條例包括有嚴格的新排放標準，如下： • PM—0.01 g/bhp-hr （微粒排放） • NOx—0.20 g/bhp-hr （氮的氧化物） • NMHC—0.14 g/bhp-hr （非甲烷碳氫化合物） PM 排放標準于2007年起全面生效，氮氧化物和非甲烷碳氫化合物排放標準在2007-2010年間逐步采用。詳細文章請見英文內容: On December 21, 2000 the EPA signed emission standards for model year 2007 and later heavy-duty highway engines （the California ARB adopted virtually identical 2007 heavy-duty engine standards in October 2001）. The rule includes two components: （1） emission standards, and （2） diesel fuel regulations. The first component of the regulation introduces new, very stringent emission standards, as follows: • PM—0.01 g/bhp-hr • NOx—0.20 g/bhp-hr • NMHC—0.14 g/bhp-hr The PM emission standard will take full effect in the 2007 heavy-duty engine model year. The NOx and NMHC standards will be phased in for diesel engines between 2007 and 2010. The phase-in would be on a percent-of-sales basis: 50% from 2007 to 2009 and 100% in 2010 （gasoline engines are subject to these standards based on a phase-in requiring 50% compliance in 2008 and 100% compliance in 2009）. Very few engines meeting the 0.20 g/bhp-hr NOx requirement will actually appear before 2010. In 2007, most manufacturers opted instead to meet a Family Emission Limit （FEL） around 1.2-1.5 g/bhp-hr NOx for most of their engines with a few manufacturers still certifying some of their engines as high as 2.5 g/bhp-hr NOx+NMHC. In addition to transient FTP testing, emission certification requirements also include: • SET test, with limits equal to the FTP standards, and • NTE testing with limits of 1.5 × FTP standards for engines meeting a NOx FEL of 1.5 g/bhp-hr or less and 1.25 × FTP standards. for engines with a NOx FEL higher than 1.5 g/bhp-hr. Effective for the 2007 model year, the regulation maintains the earlier crankcase emission control exception for turbocharged heavy-duty diesel fueled engines but requires that if they are emitted to the atmosphere, they be added to the exhaust emissions during all testing. In this case, the deterioration of crankcase emissions must also be accounted for in exhaust deterioration factors. The diesel fuel regulation limits the sulfur content in on-highway diesel fuel to 15 ppm （wt.）, down from the previous 500 ppm. Refiners will be required to start producing the 15 ppm S fuel beginning June 1, 2006. At the terminal level, highway diesel fuel sold as low sulfur fuel must meet the 15 ppm sulfur standard as of July 15, 2006. For retail stations and wholesale purchasers, highway diesel fuel sold as low sulfur fuel must meet the 15 ppm sulfur standard by September 1, 2006. Refiners can also take advantage of a temporary compliance option that will allow them to continue producing 500 ppm fuel in 20% of the volume of diesel fuel they produce until December 31, 2009. In addition, refiners can participate in an averaging, banking and trading program with other refiners in their geographic area. Ultra low sulfur diesel fuel has been introduced as a “technology enabler” to pave the way for advanced, sulfur-intolerant exhaust emission control technologies, such as catalytic diesel particulate filters and NOx catalysts, which will be necessary to meet the 2007 emission standards. The EPA estimates the cost of reducing the sulfur content of diesel fuel will result in a fuel price increase of approximately 4.5 to 5 cents per gallon. The EPA also estimates that the new emission standards will cause an increase in vehicle costs between $1,200 to $1,900 （for comparison, new heavy-duty trucks typically cost up to $150,000 and buses up to $250,000）.