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Hitachi ZX-5 Excavators Meet Interim Tier 4 Regulations

The new series of Hitachi Zaxis Dash-5 Excavators feature Isuzu engines with cooled exhaust gas recirculation (EGR) and exhaust filters consisting of a diesel oxidation catalyst/diesel particulate filter to meet the 2011 EPA Interim Tier 4 (IT4)/EU Stage IIIB emissions regulations mandated for 174- to 750-hp diesel engines.

“Hitachi believes this is the simplest IT4 solution,” said Mark Wall, product marketing manager for Hitachi construction excavators in the Americas. “And it continues to deliver the productivity, fuel efficiency and reliability customers expect from Hitachi.”

Hitachi’s approach to meeting IT4 regulations is an evolution of the clean-burning and fuel-efficient Tier 3/Stage IIIA Isuzu engine platform used in Hitachi Dash-3 Excavators.

The Isuzu cooled EGR engine platform for IT4 compliance is less complex to maintain compared to SCR (selective catalytic reduction) systems. “Unlike SCR, this IT4 solution doesn’t require liquid urea to achieve the necessary emissions reduction. There aren’t any other fluids to acquire, fill and store on jobsites,” Wall said. “EGR requires just one fluid – diesel fuel.”

Many Hitachi Dash-3 Excavators featuring Isuzu engines with Tier 3/Stage IIIA cooled EGR technology are running reliably today, according to the company, and the Interim Tier 4/Stage IIIB units will be a natural next step for Hitachi dealers to sell and support. “Hitachi dealers are ready to service and support these new engines and optimize the overall efficiency of the excavator,” Wall said.

Hitachi excavators currently using Tier 3 Isuzu engines range from the ZX75US-3 through the ZX850LC-3. The new IT4 models rolling out over the next several months are the ZX250LC-5, ZX290LC-5, ZX350LC-5, ZX470LC-5, ZX670LC-5, and ZX870LC-5.
Hitachi Construction Machinery Co.,