Doosan has introduced the new DX420LC-5, DX490LC-5 and DX530LC-5 Tier 4-Final excavators that replace the T4-I Dash 3 versions. The engines use high-pressure common-rail fuel delivery systems with cooled EGR, DOC, and SCR after-treatment, which requires diesel exhaust fluid (DEF). A mass airflow sensor helps manage airflow from the variable geometry turbocharger and optimise fuel delivery to the combustion chamber based on engine air intake volume and rpm, resulting in improved fuel efficiency. An auto-shutdown feature will shut down the engine when the preset idle time is met. Smart Power Control (SPC), a new selectable feature, consists of two systems, variable speed control and pump torque control, that work together to improve machine efficiency.