Analysis of Carbon Dioxide Emissions and Vehicle Specific Power in Two Sedan Vehicles with Different Transmission Systems Under Traffic Conditions in Lima Metropolitan Area

The study analyzes the carbon dioxide (CO2) emissions in two sedan type vehicles with different transmission systems, manual and automatic, in relation to speed and Vehicle Specific Power (VSP) under various traffic conditions in the metropolitan area of Lima, Peru. The results indicate that in both vehicles the CO2 emission factors are higher at speeds below 20km/h due to increased fuel consumption during accelerations, and they decrease with an increase of the average speed. The CO2 emission factor is slightly influenced by the type of transmission. With the automatic transmission the CO2 mass flow rates are slightly higher than the values with mechanical transmission. However, for both vehicles, no clear correlation was found between the CO2 mass flow trend curves, so they were divided into different VSP bins. Median statistical values of CO2 mass flow rates identifies a decrease as the VSP bin decrease, but there is an increase after reaching the Bin 11. Median CO2 mass flow rate results in each VSP bin are similar with both transmission systems, suggesting that VSP bin is a valid parameter for comparing CO2 emissions in different traffic conditions in urban areas as Lima, Perú.