Cummins produces first Tier 4 interim engines
| September 21, 2010
The engines also received California Air Resources Board certification to enable 50-state compliance.
The QSB6.7 engine is certified to a higher power output of 300 horsepower, while the QSL9 engine increases output up to 400 horsepower. These engines are built at the Cummins Rocky Mount plant in North Carolina.