Older diesel-powered vehicles will see a 10-percent reduction in particulate emissions right off the bat by using the new fuel, while new diesel engines designed to take advantage of it will cut their particulate emissions by 95 percent. This is due to the fact that the new ULSD contains only 15 parts per billion of sulfur, compared to the old fuel's 500 parts per million. The next major step on this path comes on January 1st, when all diesel engines sold in the United States will have to meet these stricter emissions standards. Until then, you can spot which pumps are offering ULSD by looking for the sticker above. Other stickers touting the new fuel can be found here.
[Source: Diesel Technology Forum]