Dr Dimitrios Savvidis has been one of the main speakers in the workshop "Regulación de la Eficiencia Energética en Vehículos Pesados" organized by the Mexican Ministry of Energy in Mexico on 29-30th of September 2015. A meeting with the Mexican Universidad Autónoma Metropolitana (UAM) has taken place in order to exchange views on the latest developments for calculating CO2 emissions and fuel consumption from Heavy Duty Vehicles.