October 15th, 2006 is the date when the US started to sell low-sulfur diesel (ULSD) nationwide. According to the Diesel Technology Forum (DTF), the change happened seamlessly and no incidents have been reported. More ULSD is being refined, 93 million barrels in July 2007, which is almost double what was refined the same period from last year (54 million). This number will increase as the U.S. heads towards full ULSD use in 2010.
Availability has also exceeded expectations. The target was to have at least 80 percent of diesel stations pumping ULSD, currently 90 percent of them offer this fuel. Nevertheless, about 25 percent of the diesel in the U.S. is non-ULSD, although very little of it goes to road vehicles.
The EPA estimates that SOx emissions have been lowered significantly thanks to this measure, by approximately 100,000 tons. CO pollution has gone down 70,000 tons as well. According to Diesel Forum, a 2007 diesel truck emits just one-sixtieth of the soot exhaust of one produced in 1988. Nevertheless, not until the complete US truck fleet is renewed by 2020 will the full effects be fully noticeable, since new trucks will have fine particullater matter filters which were impossible to fit before.
The good news is that the new fuel allows owners of current vehicles to retrofit particullate filters. Congress is currently considering appropriations for the national clean diesel retrofit program and could provide up to $200 million this year to modernize existing vehicles and equipment.