12 January 2010
Cummins received certification from the Environmental Protection Agency (EPA) and from the California Air Resources Board (ARB) for its 2010 Heavy-Duty big-bore ISX15 and MidRange ISB6.7, ISC8.3 and ISL9 engines.
The EPA 2010 emission standards, effective from January 1, 2010, are 0.2 g/bhp-hr for NOx and 0.01 g/bhp-hr for PM emissions. However, under the US and California emission regulations, manufacturers can certify engines to emission levels (family emission limits, FEL) higher than the applicable standard and cover the difference by their emission credits.
Cummins will utilize selective catalytic reduction (SCR) technology to meet the 2010 standards. Cummins, who initially intended to meet the standards through in-cylinder technology, committed to using SCR technology because of a “step change in performance which provides a significant increase in efficiency and durability”. Cummins expects at least 5% fuel economy improvement for the ISX15 and up to 3% improvement for the MidRange products.
According to the California ARB Executive Orders, the Cummins engines have been certified to NOx emission levels (FEL) ranging from 0.30 to 0.35 g/bhp-hr, while 2010 Volvo engines with the SCR technology have been certified to the 0.2 g NOx standard. The higher NOx FEL limit in Cummins engines—made possible by NOx credits—is potentially a source of a fuel economy advantage.
Cummins EPA 2010 engines will include an enhanced cooled EGR system and a single VGT turbocharger. The ISX15, ISL9, and ISC8.3 feature the Cummins XPI fuel system, and the ISB6.7 features an improved high pressure common rail fuel system. The new SCR catalyst is included along with the Cummins Particulate Filter, first introduced in 2007, in the Cummins Aftertreatment System. Incorporating SCR technology will also require the use of urea solution (diesel exhaust fluid, DEF) at an average rate of 2% of diesel fuel consumption.
The 2010 Cummins engine line-up covers a range of on-highway applications. The Heavy-Duty ISX15 is intended for the heavy-duty Class 8 truck market, while the MidRange ISB6.7, ISC8.3, and the ISL9 are designed for such applications as medium-duty truck, school bus, fire and emergency, and recreational vehicle markets. Later in 2010, Cummins will introduce the ISX11.9 (not yet EPA certified), to serve customers in the vocational and less-than-truckload markets.