Cummins announced that it will continue to use a variation of its current exhaust gas recirculation system for 2010 heavy-duty engines to meet the tougher exhaust emissions standards, but will need to add a selective catalytic reduction system on its medium-duty engines.

Cummins heavy-duty engines for 2010 will be part of the X family of engines and will include 11.9-, 15- and 16-liter displacements. According to Cummins, the current ISM family of engines will be retired from the North American highway market at that time.

The SCR systems slated for use on Cummins medium-duty engines will use a separate urea tank and urea dosing system in addition to the current EGR system. The tank will require regular refills, and the system will require periodic maintenance to function properly.