Motor vehicle fuels in Mexico are distributed exclusively by the national oil company Petróleos Mexicanos (PEMEX). Regulation NOM-086-SEMARNAT-SENER-SCFI-2005 defines two grades of diesel fuel:
- Automotive diesel (PEMEX) for use in on-road vehicles, and
- Marine and agricultural diesel.
The low sulfur automotive diesel grade (first introduced as Diesel Sin) replaced the earlier standard diesel of 5000 ppm (0.5%) sulfur.
The regulation sets automotive diesel fuel sulfur levels at 500 ppm with a scheduled reduction to 15 ppm. The following is the phase-in schedule for ultra-low sulfur (15 ppm) on-road diesel:
- February 2007—Northern frontier region that borders the USA,
- February 2009—Metropolitan regions of Guadalajara, Monterrey and the Valle de México,
- September 2009—Nationwide.
However, the 2009 natiowide deadline has not been met and on-road diesel with sulfur content above 15 ppm continues to be sold in parts of Mexico.
Diesel fuel for marine and agricultural applications is colored and has an upper sulfur limit of 5000 ppm.