Cummins Inc. recently achieved a major industry milestone by commencing production and supply of the first EPA Tier 4 Interim and EU Stage IIIB certified engines and after-treatment for early installation by off-highway equipment customers. The latest-generation QSB6.7 and QSL9 engines are built at the Cummins Rocky Mount plant in North Carolina for customers in North America and East Asia, with the Darlington plant in the U.K. supplying European customers. The new emissions regulations take effect Jan. 1, 2011, for engines over 173 hp (129 kW), with particulate matter reduced by 90 percent and oxides of nitrogen by almost 50 percent compared with the current Tier 3 and Stage IIIA standard. The QSB6.7 engine is certified to a higher power output of 300 hp (224 kW), while the QSL9 engine increases output up to 400 hp (298 kW). The 6.7-liter and the 9-liter engines have received EPA and EU emissions certification as integral systems with Cummins particulate filter exhaust after-treatment, enabling a unique level of integration and packaging efficiency. Before finalization of the engine build specification for production release, the QSB6.7 and QSL9 underwent an extensive series of field tests on commercial operations to validate performance and in-service reliability. The engines achieved up to five percent improved fuel efficiency and faster engine response, boosting machine productivity.

"With the production release of the QSB6.7 and QSL9 engines for 2011 emissions, Cummins builds on its early leadership in Tier 4 development work, concept installation and field testing," says Hugh Foden, executive director, Cummins Off-Highway Business. "Although much of the Tier 4 emissions technology is new to the off-highway industry, it is not new to Cummins. Key enablers, such as the Cummins particulate filter after-treatment, exhaust gas recirculation and variable geometry turbochargers were available from within Cummins own technology portfolio and successfully used with our EPA 2007 on-highway engines. With this proven technology base, we have been able to accelerate our Tier 4 Interim program and go beyond meeting stringent emissions levels to focus on performance deliverables. We have done what we said we would do by optimizing machine integration, improving fuel efficiency and enhancing engine response. With these benefits, we anticipate a strong preference from operators toward Cummins Tier 4 powered equipment."

The 6.7-liter and 9-liter engines are among the most widely used in the off-highway industry within their power range. Over 30 power ratings will be available for Tier 4 Interim and Stage IIIB applications, with a wide range of installation configurations applicable to all types of construction, agricultural and industrial equipment. In addition to approval by the U.S. Environmental Protection Agency (EPA) and European Union (EU) regulatory agencies, the QSB6.7 and QSL9 engines have also received California Air Resources Board (ARB) certification to enable 50-state compliance.