“…The CO₂ emissions (g/km) of each bus type were calculated using the relation: CO₂ emissions (g/km) = Fuel Consumption (l/100 km) × Emission Factor [ 78 ]. Here, the emission factor corresponds to the CO₂ produced per liter of diesel fuel combusted, and is established at 2680 g of CO₂ per liter [ [79] , [80] , [81] ]. This value is derived from the inherent carbon content of diesel and the understanding that the combustion of 1 g of carbon yields approximately 3.67 g of CO₂.…”