Proposed Index for Assigning an Environmental Label to Passenger Cars

At present, the classification of vehicles by means of the environmental label aims to positively distinguish the most environmentally friendly vehicles and to be an effective instrument at the service of municipal policies, both to restrict traffic during high pollution periods and to promote new technologies through tax benefits and other incentives related to mobility and the environment. However, there is a great deal of controversy about the awarding of this environmental label, since it is basically based only on the year of manufacture of the vehicle and the type of fuel it uses, without taking into account many other factors that influence the environmental characterization of a vehicle. This paper presents a proposal for an index to characterize passenger cars from an environmental point of view, considering other additional factors, such as tire wear and particulate emissions during braking. The proposed index is applied to a series of passenger cars representative of the segments currently present in the Spanish market. The index considers seven vehicle parameters. Up to three cases with different parameter weights are analyzed. This index provides greater discrimination of the environmental performance of vehicles than the current eco-labeling system, in each of the three cases studied.