The Mexican government published final emissions standards for engines used in heavy-duty trucks and buses and complete heavy-duty vehicles, NOM-044-SEMARNAT-2017 on February 19, 2018. Starting January 1, 2021, all new heavy-duty vehicles sold in Mexico will be required to meet the best-in-class, filter-based standards, equivalent to those currently in place in the rest of North America and the European Union. The Euro VI and US 2010 options are introduced in 2019, along with much weaker Euro V and US 2007 options, which are allowed over a two-year transition period. The soot-free standards become the only regulatory option on January 1, 2021.