Cummins Inc. highlighted its new Tier 4 Interim QSB3.3 engine at ConExpo-Con/Agg. The company says the engine has an increased power capability to 120 horsepower, one of the highest in the industry for an engine of its size, representing an 11-percent increase in power output above the current Tier 3 engine. According to the company, the power increase is made possible by the more-efficient combustion realized by the aftertreatment simplicity of the Cummins Compact Catalyst, specifically developed to meet EPA Tier 4 Interim emissions taking effect Jan. 1, 2012. The catalyst is less than 20 inches long and removes particulate matter by oxidation with simple exhaust flow-through operation.