This study presents a model of pollutant emissions (CO, CO2, and HC) based on the construction characteristics of different vehicle models in the city of Cuenca, Ecuador. For this purpose, information on the most representative M1 category vehicles in the city was collected from the Vehicle Technical Inspection (RTV) database. The correlation between different variables such as year of manufacture, vehicle weight, RPM at maximum torque, maximum torque, cylinder capacity, and pollutant emissions was analyzed. Also, emission factors were calculated for the most popular vehicles and the level of uncertainty of the study was determined as category B. The results obtained indicate that the year of manufacture is the construction variable that has the greatest influence on vehicle emissions. It was observed that, at 800 RPM, the year of manufacture influences a 43% increase in CO emissions, while, at 2500 RPM, emissions increase to 59%. In the case of CO2, an increase of 54% was observed at 2500 RPM, while, for HC at 800 RPM, the increase was 52%. However, by increasing the speed to 2500 RPM, emissions decrease to 30%. In addition, it was found that the gear change directly influences the amount of vehicle emissions; annual CO2 emissions are higher in the third and fifth gears due to the time the vehicles circulate in these gears. Finally, it was identified that the Brand 2, Model A and Brand 1, Model F vehicles generate the highest amount of annual CO emissions.