Doosan brings Tier 4 Final loaders to market

Doosan introduced its first Tier 4 Final-compliant wheel loaders – the DL300-5, DL350-5, DL420-5, DL450-5 and DL550-5. The loaders have a net horsepower range of 271 hp (in the DL300-5) to 379 hp (in the DL550-5), the company says. According to Doosan, the five new models replace Tier 4 Interim models and are powered by Scania diesel engines. The engines are optimized for use with a high-pressure common-rail fuel delivery system and a cooled exhaust gas recirculation system, according to Doosan. The loaders use a diesel oxidation catalyst to reduce particulate matter and selective catalyst reduction (SCR) after-treatment to reduce nitrogen oxides. In addition, the loaders use a variety of after-treatment systems as part of the Tier 4 compliance, such as diesel exhaust fluid (DEF), which is used with SCR technology and stored in a DEF tank.