The People of America's Oil and Natural Gas Indusry

Breathe Deeply

Jane Van Ryan

Jane Van Ryan
Posted July 7, 2009

Despite what you may have heard, the nation's air quality has improved markedly over the past several years. And part of the air quality improvement can be attributed to a major change in diesel fuel.

In June 2006, refiners began reducing the amount of sulfur in diesel fuel to make Ultra-Low Sulfur Diesel (ULSD), which is supplanting traditional diesel fuel formulations during a transition period determined by the U.S. Environmental Protection Agency.

Starting in the fall of 2006, the new fuel was sold at service stations for use in cars and trucks. Now it's moving into the marketplace for off-road vehicles, and soon it will be used to power marine and locomotive engines. In 2014, it will become the only diesel fuel available in the United States, but California was an early adopter--it's been the only type of diesel fuel available in the state since 2006.

The production of ULSD also facilitated the manufacturing of cleaner-burning vehicles and engines. Equipped with new pollution control devices, this new breed of diesel cars and trucks was introduced to the public in 2007. And today the combination of ULSD fuel and new vehicular technologies is having a major impact on air quality.

According to a new study on heavy-duty diesel engines used in large trucks and buses, the fuel/engine combination is reducing most pollutants from tailpipes by more than 90 percent. The fine particulate matter (soot) emission has been reduced by 99 percent from the allowable level in 2004, and is even 90 percent lower than 2007 requirements. Emissions of carbon monoxide, hydrocarbons and other air toxins are also much below the required levels. And nitrogen oxide, which can contribute to the formation of smog, is 10 percent below the required level.

The study, called the "Phase 1 Report" of the Advanced Collaborative Emissions Study (ACES), was conducted by the Southwest Research Institute under the oversight of the Coordinating Research Council.

Read more information about ULSD fuel.