Though December marks the end of the transition period and the introduction of ULSD at pumps nationwide, EPA surveys show that all fueling stations actually met this requirement several months ago. Data from EPA's ULSD pump survey, began in the Fourth Quarter of 2006, indicates that 100 percent of highway diesel fuel pumps were dispensing ULSD at the end of September. In addition, the sulfur content of the tested fuel averages seven parts per million (ppm), meaning that it's about 97 cleaner than the sulfur-filled (500 ppm) fuel that was used in the U.S. back in 2006. That's what we call progress.
[Source: Clean-Diesel | Image: Mulad – C.C. License 2.0]