Actually, in the US it was 500ppm in 2007 (LSD), and by the end of 2010 it will all be ULSD (15ppm sufur) for onroad vehicles. 2014 is when the exemptions for

Actually, in the US it was 500ppm in 2007 (LSD), and by the end of 2010 it will all be ULSD (15ppm sufur) for onroad vehicles. 2014 is when the exemptions for some small offroad vehicles and the like are removed. http://en.wikipedia.org/wiki/Ultra-low_sulfur_diesel#United_States http://en.wikipedia.org/wiki/Ultra-low_sulfur_diesel#United_... Also, soot isn't directly related to sulfur in fuels. It's the suit removing mechanisms in newer diesel vehicles that are ruined by sulfur, so newer vehicles can't run fuel with sulfur in it without incurring a large repair bill. An older diesel vehicle that belches out soot will continue to do so, regardless of sulfur content.