Efficient BlueTec diesel technology for Daimler commercial vehicles

OFFICIAL PRESS RELEASE

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160,000 BlueTec vehicles on the roads in everyday use
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400 million liters of diesel fuel saved
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100 million tonnes of CO2 emissions avoided

Stuttgart, Jun 13, 2008 - Daimler has been offering its highly-efficient BlueTec diesel technology for commercial vehicles since early 2005 - and with great success. Since then, around 160,000 BlueTec commercial vehicles have taken to the streets of Europe, including Mercedes-Benz heavy trucks and Vario vans, as well as Mercedes-Benz and Setra buses. Over 90 percent of these vehicles already fulfill the Euro5 emissions standard not due for introduction until autumn 2009. So far, these BlueTec vehicles have saved their operators around 400 million liters of diesel fuel and the environment 100 million tones of CO2 emissions. In total, they have covered well over one billion kilometers - providing outstanding proof of their capabilities. With the order of Mercedes-Benz city buses from Singapore Mass Rapid Transit (SMRT), environmentally-friendly BlueTec technology is now finding its way into South East Asia.

The new BlueTec diesel technology is the most efficient means of fulfilling EU4 and EU5 emissions regulations for commercial vehicles. So far, BlueTec is unique in combining ecological requirements with economic factors. Compared to the previous EU3 standard, exhaust gases contain at least 80 percent fewer particulates and up to 60 percent less nitrogen oxide. At the same time, BlueTec vehicles consume between two and five percent less diesel fuel. Over an average distance of 150,000 kilometers, this equates to a saving of 1,500 to 2,000 liters of fuel per year.

BlueTec is based on redesigned engines and a highly effective form of exhaust gas after-treatment. Firstly, improved combustion efficiency reduces base engine emissions of soot and other particulates to the levels normally found in pre-filtered exhaust gas. Nitrogen oxides are then converted into harmless nitrogen and water vapor in a chemical catalytic reaction within an exhaust gas after-treatment system that uses the SCR principle (SCR = Selective Catalytic Reduction) with the addition of AdBlue, an aqueous urea solution. Controlled by the engine electronics, exactly the right amount of AdBlue is sprayed from a separate tank into the hot exhaust gas, where it is hydrolyzed into ammonia. AdBlue is standardized by DIN 70070 and available at fuel stations throughout Europe.

In re-designing the engine, the priority was the further reduction of base emissions with a clear focus on the fewest possible combustion particulates and minimal fuel consumption. Compromises were always necessary prior to the decision for exhaust gas after-treatment. In a combustion system designed for low particulate emissions and minimal fuel consumption, there are always higher levels of nitrogen oxides, and vice versa. Once released from this thermodynamic conflict, it was possible to design engines specifically focused on low fuel consumption and low particulate emissions. The after-treatment of the exhaust gas using the SCR principle enables the necessary reduction of nitrogen oxides.

The successive introduction of BlueTec diesel technology began in early 2005, initially as a special option on Mercedes-Benz heavy trucks for long-distance haulage. From the very start, customers could order BlueTec 4 to meet the EU4 standard (in effect since October 2006) or, alternatively, BlueTec 5 to meet the standards that will come into effect as of October 2009. Over 90 percent of customers opted immediately for the BlueTec 5 version. The technology was successively expanded to cover all Mercedes-Benz heavy trucks, the Econic and Unimog special vehicles, and all buses built by Mercedes-Benz and Setra. The new BlueTec diesel technology has been standard fit on these vehicles within Europe since autumn 2006.

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