Medium- and heavy-duty trucks motor coaches and transit buses - collectively medium- and heavy-duty vehicles or MHDVs - are used in every sector of the economy The fuel consumption and greenhouse gas emissions of MHDVs have become a focus of legislative and regulatory action in the past few years Reducing the Fuel Consumption and Greenhouse Gas Emissions of Medium- and Heavy-Duty Vehicles Phase Two is a follow-on to the National Research Councils...