The Cat C18 ACERT engine is built and tested to meet your most demanding applications. Three C18 ACERT engine options are available in this machine: A U.S. EPA Tier 4 Final/EU Stage IV Technology with aftertreatment, Tier 3 equivalent ACERT engine without aftertreatment, or a Tier 2 equivalent ACERT engine without aftertreatment. Fully integrated electronic engine controls works in concert with the entire machine to make your fuel go farther. Use less fuel idling with Engine Idle Shutdown. Maximized durability with Delayed Engine Shutdown.