Navistar is a manufacturer of medium- and heavy-duty trucks, school buses, military vehicles, and diesel engines. Its principle markets are North America and Latin America. Its trucks are sold through over 800 dealers in the United States, Canada, and Mexico. It currently commands a 17% share for its core products, which include class 6 through 8 trucks and school buses. The company previously struggled to develop an unconventional diesel emission technology, or EGR, to meet 2010 EPA guidelines, which caused its market share to plummet to 16% in 2015 from 36% in 2009. In 2018, manufacturing revenues were approximately $10 billion.