Iveco and FPT Industrial say they are ready to meet Euro 6 emissions regulations for medium- and heavy-duty trucks, using SCR (selective catalytic reduction) alone.
The technology will, they say, be introduced on two new Cursor and Tector engine ranges for trucks and buses, which will both feature no EGR (exhaust gas recirculation).
Details are sketchy, but the 'SCR only' technology features "optimised combustion and after-treatment systems" using "breakthrough patented control technology in which a very high NOx conversion efficiency [over 95%, compared with 80—85% at best] is achieved".
"EGR has its place, but for heavy commercial vehicles … the technology that reduces fuel and operating costs to a minimum [SCR] is the correct choice," says Iveco CEO Alfredo Altavilla. "FPT Industrial's 'SCR Only' exhaust after-treatment fulfils this need."
Reading between the lines, thet SCR improvement comes from a new generation of Zeolite-based, compact SCR unit, with improved AdBlue dosing (using turbulence mixer technology) and thermal management, as well as better sensing and control.
Beyond those, Iveco also cites its high cylinder pressure and injector nozzle pressures (up to 2,200 bar), achieved through changes to the crankcase and cylinder head designs that make for increased structural rigidity, higher coolant flows and increased swept volumes.
A new electronic control unit has also been introduced to manage both engine parameters and after-treatment control, integrating engine, SCR and full-flow DPF (diesel particulate filter) functions.
For Cursor engine versions using the variable geometry turbocharger, electronic control has also been introduced to optimise load response at low engine speeds and to increase the effectiveness of the engine brake. Also, all engines will now harness flap type engine brake valves to support passive DPF regeneration and improve engine brake performance by up to a claimed 30% compared to current Euro 5 engines.
Incidentally, to prevent any oil mist carried in engine blow-by gases, very high performance oil separation systems have been introduced –important to prevent oil burning and consequent DPF contamination. For Cursor engines, an oleophobic centrifugal oil separator has been implemented, while for the Tector, a valve cover integrated coalescent type blow-by filter is being used.
As for the box itself, Iveco talks of a compact system, with all components integrated, including DOC (diesel oxidant catalyst), DPF, SCR and CUC (clean-up catalyst).
