environmental labels for motorcycles: They are mandatory?

Makes about two years system was introduced in Spain environmental classification for four-wheel vehicles based on their emissions.

Environmental labels classify vehicles relative to the level of contaminants through five levels: “unlabeled”, “B”, “C”, “ECO” Y “ZERO”. This system is already in use in some cities like Madrid or Barcelona to discriminate vehicles that may or may not enter urban areas depending on environmental pollution.

Now, This classification also reaches motorcycles. They are mandatory on bikes? No, at the same happens in cars, installation is not mandatory today, although it is advisable.