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SCR: a winning strategic choice
Reducing nitrogen oxides (Nox) by treating exhaust gases downstream of the engine by means of a catalytic converter: this is Iveco’s strategic choice. This makes it possible to optimise the combustion process and simultaneously reduce fuel consumption and particulate emission. The good handling assured by Cursor engines is not affected, while reliability and fuel consumption are actually improved without the need to equip the vehicle with an oversized cooling system and without limiting the engine’s maximum power delivery.
Compared to the EGR (Exhaust Gas Recirculation) system adopted by some of our competitors, the SCR system brings extraordinary benefits for the environment – and also Stralis customers:
- more power for the same cylinder capacity;
- lower weights;
- lower fuel consumption due to the higher injection pressure;
- lower energy uptake for heat dissipation;
- fewer oil changes for the same mileage.
How Selective Catalytic Reduction works
The SCR exhaust gas post-treatment system uses a catalytic converter that converts nitrogen oxides Nox into harmless nitrogen and water by means of a chemical reaction. The chemical reaction takes place when an additive known as AdBlue – a solution of 32.5% urea and water - is added to the exhaust pipe upstream of the catalytic converter in very precise quantities. AdBlue is non-toxic, colourless, non-flammable and thus easy to store – its physical and chemical properties are laid down in DIN standard 70070.
The whole system is managed by a dedicated electronic control unit. The amount of AdBlue injected is regulated according to vehicle and environmental parameters. The system ensures that standards are complied with even under extreme environmental conditions, without affecting vehicle performance. AdBlue consumption is approximately 1 litre every 20 litres of diesel and a full tank of Adblue lasts for thousands of kilometres. This system makes a particulate filter superfluous because the particles are mostly removed during the combustion stage and any remaining particles are burnt in the catalytic converter.
SCR technology is designed to last the vehicle’s entire lifetime and does not require any particular maintenance operations.
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