Monday will mark the one-year anniversary of ultra low sulfur diesel's arrival at U.S. fueling stations nationwide.

Initial concerns about fuel availability and the performance of heavy-duty trucks designed specifically for ULSD have waned, thanks to an absence of problems transitioning to the clean diesel system, according to the Diesel Technology Forum.
More than 93 million barrels of ULSD were refined in July of this year, compared with just 54 million a year earlier, according to the U.S. Energy Information Administration. ULSD now accounts for more than 75 percent of all distillate fuel production, and EPA estimates that more than 90 percent of all retail service stations that have diesel fuel are now carrying ULSD - exceeding the required 80 percent minimum level. Since October 2006, more than 838 million barrels of clean diesel fuel have entered the U.S. distribution system.
"The transition to ULSD fuel has been nearly seamless, with virtually no supply interruptions nor technical glitches," said Allen Schaeffer, executive director of the Diesel Technology Forum. "Like the switch from leaded to unleaded gasoline, this transition to clean diesel fuel is fundamentally transforming diesel technology to be a leading solution for reducing energy consumption, lowering greenhouse gas emissions and meeting aggressive clean air standards."
ULSD is required for all new 2007 clean diesel heavy-duty commercial truck engines and new diesel passenger cars and SUVs. Its use also allows for the modernizing of some existing engines and equipment with emissions control technology such as particulate filters.
The U.S. Environmental Protection Agency estimates that this year, thanks to a combination of cleaner diesel fuel and new engine technology, sulfur oxide emissions (a contributor to acid rain) from heavy-duty trucks will decrease by more than 100,000 tons and carbon monoxide emissions by more than 70,000 tons.
However, the most significant benefits of clean diesel will be realized when new trucks have largely replaced the existing fleet in 2020. At that time, EPA predicts 2 million fewer tons of nitrogen oxides (or NOx, a component of smog) and 83,000 fewer tons of fine particulate matter (or soot annually), thanks to clean diesel.
A 2007 diesel truck emits just one-sixtieth the soot exhaust of one produced in 1988.