Stralis Euro 4 - Euro 5

Iveco chooses SCR technology to ensure the medium and heavy commercial vehicle ranges comply with the Euro 4 and Euro 5 Directives.

Cutting down nitrogen oxides in the exhaust system by means of an additive – AdBlue – is the solution Iveco has adopted on the medium and heavy range. This ensures respect
for the environment while reducing running costs and, therefore, guaranteeing an increase in profitability – two fundamental factors for Iveco. Choosing this exhaust after-treatment method also means vehicles will meet emission standards established in the Euro 5 Directive ahead of time. By adopting SCR technology as early as the second half of 2005, Iveco will be able to supply vehicles that enable road transport operators to benefit from incentives approved by a number of European countries to encourage use of vehicles
complying with Euro 4 & 5 emission levels in advance.

Dilemma posed by the Euro 4 and Euro 5 directives.

The Euro 4 Directive poses a problem for Iveco – and other manufacturers too – that is difficult to resolve, namely, to reduce particulate emissions by 80% and nitrogen oxides by 30% compared to Euro 3 levels. The Euro 5 Directive then requires a further 40% reduction for nitrogen oxides. Today,
given current know-how and fuel injection technologies, action taken on the combustion front can only reduce the percentage of one pollutant by increasing the emissions of the other. This is why exhaust gases must be subjected to exhaust after-treatment in order to complete action taking place
within the engine. The same situation exists as regards compliance with Euro 5 emission limits.
At this point manufacturers have two options. The percentage of nitrogen oxides in the combustion chamber can be reduced by lowering temperatures as a result of adding exhaust gases to air aspirated at the time of combustion. These gases, which replace part of the engine's air intake, must be carefully
dosed and cooled inside a heat exchanger fed by the engine cooling system. Simultaneously, injection timing is retarded. However, any drop in combustion temperature causes a drop in engine efficency.
The other problem is a marked increase of particulate matter in the exhaust, especially in recirculated exhaust gases. This can lead to contamination of the lubricant, which must therefore have a greater particulate dispersion capacity. Particulate is treated after the engine stage by using a filter in the exhaust silencer. While these factors have little effect on low-capacity engines, the impact becomes significant as engine power increases. Exhaust gas recirculation is referred to as EGR. Recently this solution has been adopted by some manufacturers on medium and heavy trucks in order to meet
Euro 4 standards. For Euro 5, given current technologies the EGR + particulate filter system is not sufficiently effective for high-powered engines, even though this solution doesn't require the addition of an additive to the exhaust. Compared to Euro 3, the EGR solution means an increase in vehicle

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