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
weight.

The SCR – Selective Catalytic Reduction – solution is the alternative approach chosen by Iveco and the majority of medium and heavy commercial vehicle manufacturers. It consists of optimising engine combustion to achieve maximum reduction of the particulate content in exhaust gases. Engine
performance is improved and this leads to lower fuel consumption. To eliminate the percentage of nitrogen oxides in exhaust gases that exceed the limit, first a reducing agent is added to the gases and then these are treated by a catalytic filter in the silencer. This procedure converts the nitrogen
oxides into entirely harmless nitrogen and water vapour. The reducing agent is ammonia, stored in the form of a urea-based aqueous solution and marketed under the brand name AdBlue.
SCR technology means that particulate filtration is superfluous inasmuch as this type of emission is cut down directly during the combustion phase, while the catalytic converter burns up the remaining particulate simultaneous with treatment of the nitrogen oxides.
Again in this case the vehicle weight increases compared with an equivalent Euro 3 version.

Why Iveco decided to adopt the scr system.

The SCR system chosen by Iveco represents the ideal compromise between two fundamental objectives engine designers had set themselves in order to meet customer requirements. On the one hand, improve engine performance to reduce fuel consumption and running costs, at the same time extending the life of engine components; on the other, comply with emission limits established by European authorities to safeguard the environment. Clearly, the progressive reduction in fuel consumption per tonne of goods transported means engines give off less CO2, the gas responsible for warming the planet.
Iveco began studies on SCR reduction in 1994 at its Arbon Research and Development Centre in Switzerland (Iveco Motoren Vorschung) as a member of a consortium created together with other manufacturers. Iveco has also explored the EGR solution and adopted it on the light commercial
vehicle range, given that for this type of use it represents the ideal compromise between various factors (consumption, weight, cost).
Given the high average annual kilometres travelled by medium and heavy vehicles, the benefit obtained by reducing fuel consumption became the top priority. Furthermore, the SCR approach has no negative effect on lubricant quality or the interval between oil changes. In fact the low particulate content in the combustion chamber further extends these intervals. Similarly, the system isn't sensitive to the
sulphur content of diesel fuel.
Unlike EGR technology the SCR approach doesn't require increased use of the engine cooling system.
Everyone knows that high powered vehicles need larger radiators and the size of these poses serious layout problems on heavy vehicles. Also, increasing fan performance drains power and negatively affects fuel consumption.

A chance to anticipate the Euro 5 directive

A basic advantage of the SCR system is that it can satisfy both Euro 4 and Euro 5 emission level requirements, which means Iveco has been able to develop a solution for both emission levels simultaneously. Thanks to the modern architecture of its engines, and especially the electronic control injector pumps operated by a camshaft located directly in the cylinder block, Iveco has been able to develop a new injection system with higher pressures and finer fuel atomisation. For Iveco Cursor engines AdBlue consumption is 4-5% for Euro 4, or around 1.5 l/100 km, and slightly higher for Euro 5. For instance, a urea consumption of 60 l gives an autonomy of over 3,500 km.
The AdBlue injection system has been tested in extreme climate conditions to take into account the physical properties of this additive and, above all, its progressive crystallisation below –11°C. Test campaigns have been organised in Scandinavia and Spain, while numerous customer vehicles are undergoing long-term testing.
So Iveco is ready to offer heavy Stralis vehicles in both a Euro 4 and Euro 5 version simultaneously.
Iveco expects demand for these vehicles will come mainly from countries offering financial incentives for adopting the European Directives ahead of the date fixed for their introduction. Germany, Switzerland and Austria are good examples.

Iveco Euro 4 and Euro 5 models available before relevant mandatory dates

Euro 4 & 5 models are available before the mandatory dates to adopt the relevant standards, they comply with current regulations (EEC 88/77-EC1999/96-EC 2001/27) and as a priority respond to demand in markets offering financial incentives. These are the models: 4x2 tractors and 6x2 trucks, both available in two engine versions – 430 HP Cursor 10 or 480 HP Cursor 13 – all outfitted with the Stralis Active Space cab. Initial deliveries are forecast for September 2005. Because of heavy demand from Germany and Austria (in general, those countries offering incentives), deliveries for other countries in which road transport operators wish to anticipate the Euro 5 Directive will begin in November this year.