The LDV Emissions program required gasoline to meet an average sulfur standard of 120 ppm and a cap of 300 ppm beginning in 2004. Since 2006, the average standard was reduced to 30 ppm with an 80 ppm sulfur cap.
Starting January 1, 2017, EPA requires that federal gasoline will contain an average of 10 ppm sulfur on an annual basis, with the maximum sulfur allowed per batch remaining at 80 ppm at the refinery gate and 95 ppm downstream.
EPA has offered flexibility in phase in of these sulfur standards at each stage, temporarily allowing for compliance with less stringent standards by small refiners or small volume refiners in 2004-2006, 2006-2007, and again during 2017-2020.
Highway Diesel Fuel
15 ppm – Diesel fuel of maximum sulfur level of 15 ppm was available for highway use beginning in June 2006. This fuel, referred to as “ultra low sulfur diesel” (ULSD), was legislated by EPA to enable catalyst-based emission control devices, such as diesel particulate filters and NOx absorbers necessary for meeting the 2007-2010 emission standards for heavy-duty engines and the Tier 2 light-duty standards. For additional information, see the US Heavy-duty Emissions page.
*****************
There's a hidden tax....
Thousands of very intelligent peoples’ entire career is wasted as accountants and tax lawyers.
These people could have had productive careers where their lives would have meant far more to society and advanced humankind far more.