1. Bus emission measurements Matti Kytö, Kimmo Erkkilä & Nils-Olof Nylund 1.12.2009

2. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 2 Chassis Dynamometer for Heavy-Duty Vehicles Max. power:  300 kW (range 54 -110 km/h) Max. traction:  20,000 N (range 0 -54km/h) Inertia simulation: 2500 – 60,000 kg Roller diameter: 2500 mm Max. boggie load: 20,000 kg Fast IGBT control enables transient operation Texel V6 data acquisition system Driver’s aid with different dynamic driving cycles

3. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 3 Emission testing using truthful dynamic bus cycles

4. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 4 Critical emission components For urban air quality: particulates oxides of nitrogen (NOx) and specifically nitrogen dioxide (NO2) new diesel technology: increased share of NO2 in exhaust stoichiometric natural gas: close-to-zero direct NO2 For global warming: carbon dioxide (CO2) methane (CH4) Noise: gas buses emit less noise than diesel buses

5. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 5 Summary of all buses Best CNG buses

6. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 6 Newest city buses Diesel Euro 5 & EEV SCR Diesel EEV EGR + POC Diesel EEV SCR + CRT Diesel EEV SCR Notice: Tighter scaling for EEV-results

7. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 7 EEV CNG Lean-mix (malfunction?) CNG Stoich. & lean mix EEV CNG Lean-burn Newest city buses

8. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 8 Maakaasu= natural gas

9. VTT TECHNICAL RESEARCH CENTRE OF FINLAND 9