contd....
| Figure 4.8 |
Evolution of EU emission standards (light duty) |
Heavy Duty Engines
Most heavy-duty vehicles are powered by the diesel engines. Hence, the heavy duty engine emission regulations have been directed more towards reduction in NOx and PM emissions.
US Standards
The US emission standards for the engines of heavy-duty vehicles (GVW >3855 kg) are given in Table 4.4. The emission limits applicable from the model year 2007 specify a drastic reduction over the year 2004 standards. The PM standards will be fully effective from the year 2007. The NOx and NMHC standards are to be phased-in for the diesel engines between 2007 and 2010.
Emission durability is to be demonstrated over the useful life of the vehicles that varies from 8 years or 176,000 km for light heavy-duty engine vehicles (>8,860 kg <15000 GVW) to 8 years or 465,300 km for heavy heavy-duty vehicles (> 15000 kg GVW).To make the year 2007 standards effective, diesel fuel sulphur is to be reduced to 15 ppm maximum down from the earlier limit of 500 ppm.
|
