Regulacje i polityka gospodarcza · 20/11/2001

Nonroad Diesel Emissions Standards Staff Technical Paper

When we set the Tier 3 emission standards in 1998, available information indicated that the cooled exhaust gas recirculation (EGR) technology developed for highway diesel engines would be the primary means of compliance with these standards. In conducting our technology review, we have surveyed the recent engineering and scientific literature on advances in diesel emissions control. We have also reviewed information provided by engine manufacturers in support of our 2004 highway standards program, showing the considerable progress they have made in the design of robust EGR systems for use in highway engines. In addition, we have gathered information from engine manufacturers on their design plans for Tier 3 and their testing and development experience with control technologies they are likely to employ. This information shows that cooled EGR is but one of several technologies available to diesel engine manufacturers to meet the Tier 3 emission standards. This widening of technology options comes from the progress of development since 1998, but is also due to the fact that the 1998 final rule envisioned a Tier 3 program more closely aligned with future highway standards, in particul