Engineering a cleaner off-highway world

As engine manufacturers gear up to meet the next round of stringent emissions standards, equipment manufacturers are reviewing a number of design possibilities.

The Tier 4 emissions standards developed by the U.S. EPA are the most stringent to date for off-highway equipment. The new standards, due to be phased in between 2008 and 2015, will reduce PM and NOx emissions by an additional 90% over the Tier 3 standards. By all accounts, the technology exists to meet the standards. The challenge for engineers is to meet them in the most economical way for a broad spectrum of off-highway applications.

“The Tier 4 program reflects a concerted effort by the EPA, California, and the European Union to harmonize the timing and requirements for off-highway emissions regulations,” said Byron Bunker, Center Director in the EPA Office of Transportation and Air Quality in Ann Arbor, MI.