2- and 3-wheelers with 2-S propulsion are still a very serious source of air pollution worldwide in many urban areas. Therefore, every effort to reduce the emissions of those vehicles is an important contribution to improve the air quality.
In the present work detailed investigations of regulated emissions and of particle emissions of 2-stroke scooters with direct injection and with carburator were performed.
To demonstrate the emission reduction potentials some possibilities of emission improvements were grouped into steps. These technical measures were:
Particle mass and nanoparticles (number), which are amply present in 2-stroke exhaust gas and which contribute strongly to the toxicity level are still unlimited by the international exhaust gas legislation. They were extensively investigated in the present project series.
The Toxicity Equivalence (TEQ) of the emitted particle mass was evaluated by means of PAH analysis and comparison with the standards based on benzo[a]pyrene (EPA method).
It was demonstrated, that a strong reduction of particle mass emissions and toxicity is possible by means of a combination of these technical measures.
There are also further possibilities of improvements, like total filtration or use of alternative fuels.
All those technical measures can be effective in the fleet only if the necessary market conditions will be created, like:
incentives for better products, production conformity control, in-use compliance control, public information and others.