Nearly all the major equipment manufacturers—including Caterpillar, Case/New Holland/Kobelco, Komatsu, Deere, Volvo, Terex and engine specialist Cummins—plan to use a combination of exhaust-gas recirculation (EGR) and a diesel particulate filter (DPF), to meet Interim Tier 4.
Image: CNH
EGR + DPF
Photo: CNH
SCR
Photo: JCB
The other major technology for Interim Tier 4 is selective-catalytic reduction (SCR), which converts nitrogen oxides to harmless nitrogen and water by dosing exhaust fumes with small amounts of diesel exhaust fluid, an aqueous urea solution, sprayed downstream of the engine. Only JCB will meet the Tier 4 Interim rule without a DPF or SCR.
