Doosan is displaying three interim Tier 4 (iT4) compliant machines and a display engine at CONEXPO-CON/AGG.The machines include a DL450 wheel loader, a DX300LC crawler excavator and an MT41 articulated dump truck. An iT4 compliant Doosan engine is also on display. Complete details will be provided later this year regarding the entire lineup of the models with iT4 compliant engines.
"As 2011 progresses, Doosan will continue to provide further emission-related information as necessary to keep our customers informed and educated on our progression through this endeavor," said Aaron Kleingartner, segment application marketing manager.
Kleingartner said an engine technology that the company already utilizes extensively on higher horsepower engines is high-pressure common rail (HPCR) fuel injection systems. HPCR was applied to many Doosan models with Tier 3 compliant engines and will be an enabler for application of further technologies needed for iT4 and Tier 4 compliance, along with cooled exhaust gas recirculation (CEGR), diesel particulate filters (DPF), diesel oxidation catalysts (DOC) or selective catalytic reduction systems (SCR).
"It should be noted that iT4 and Tier 4, as they apply to Doosan heavy equipment, is not one set of emission standards and one compliance deadline," Kleingartner said. "IT4 and Tier 4 emission standards and compliance deadlines vary considerably among different engine horsepower ratings."
Currently, he said, iT4 compliance for Doosan products with 50- to 75-horsepower engines has already been completed. That's because iT4 emission standards are less stringent to this range of engine horsepower compared to higher (>75) horsepower engines, and changes required to achieve compliance for engines in this class were less complex.
"On the other hand, iT4 compliance for engines in the 75- to 175-horsepower class will not be required until 2012," he noted. "Our most immediate concern is iT4 compliance for 175- to 600-horsepower engines starting this year."