Meeting New Air Purity Law for Commercial Vehicles; Siemens VDO Automotive Reduces Pollutant Emissions with Modern Electronics and Mechatronics.

HANOVER, Germany -- At the IAA for Commercial Vehicles, Siemens VDO Automotive AG presents innovative components and systems that reduce pollutants from emissions. The centerpiece of Siemens VDO Automotive's presentation is a common rail diesel fuel injection system with hydraulic pressure boosting and a nitrogen oxide sensor. Poised for mass production is a second-generation particulate filter developed by Emitec, a joint venture between GKN and Siemens VDO Automotive.

Modern powerful diesel engines in commercial vehicles are the linchpin in economical freight transportation. For these engines, the stricter Euro 4 exhaust standard takes effect in October 2005. This standard requires commercial vehicles to lower nitrogen oxide emissions by 30 percent and particulate emissions by 80 percent in comparison to the Euro 3 standard.

To meet these standards, Siemens VDO Automotive is developing fuel injection technology, regulated exhaust gas recirculation, and increasing electronic sensor use. Over the medium-term, it also is necessary to employ soot filters to reduce particle emissions. Elevating injection pressure is an important factor in the reduction of emissions and fuel consumption: the higher the pressure, the finer the fuel atomization. Smaller fuel particles burn more completely and cleanly. The new Siemens VDO Automotive amplified common rail system yields injection pressures far above 2,000 bar by using hydraulic pressure boosting.

Small sensors also have a big effect. NOx sensors measure nitrogen oxide concentration and the air/fuel ratio in the exhaust gas and send this information to the engine management system. For example, if the measured values exceed permissible limits, they are counteracted by regenerating a NOx storage catalyst.

The particulate emissions from diesel engines in commercial vehicles already have been greatly reduced by improving combustion and sensors. Particles have been further reduced by additional exhaust purification systems.

Emitec, a joint venture between Siemens VDO and the British company GKN, offers the newly developed PM (particulate matter) filter. This diesel particulate filter uses open channel structures. Many small, scoop-like penetrations extend into the fine channels that are closed in conventional diesel particulate filters. The exhaust is divided into substreams and directed towards an intermediate metal fiber fleece to filter out fine diesel soot particles. These particles are burned by oxidizing the carbon with nitrogen oxides at an operating temperature above 180 degrees Celsius. Tests show that up to 80 percent of very fine particles with a 20 to 100 nanometer diameter are removed. The overall particle mass is reduced by up to 60 percent.

Siemens VDO Automotive's future focus is to prevent pollutants from being generated in the engine. New combustion processes are in the research and development stage. However, it is predicted that the engine management system will require additional information about the combustion process, including pressure in the combustion chamber. A piezo-based combustion pressure sensor developed by Siemens VDO provides this information.

In the future, an increasing amount of electronics will also be found in the engine compartment of commercial vehicles. Siemens VDO Automotive is using its experience as a supplier of engine management systems, sensors and fuel injection systems to reduce the emissions from commercial vehicles and make them more environmentally friendly.

A press photo accompanying this release can be found at www.siemensvdo.com/press.

Siemens VDO Automotive is a tier-one supplier of automotive electronic/electrical systems and components with applications covering gasoline and diesel powertrain technologies, safety and chassis systems, body electronics, plus interior products including infotainment systems. Worldwide sales reflecting fiscal year 2002/2003 totaled $9.5 billion (EUR 8.375 billion). For more information: www.usa.siemensvdo.com.

Siemens AG (NYSE:SI) is one of the largest global electronics and engineering companies with reported worldwide sales of $80.5 billion in fiscal 2003. Founded more than 150 years ago, the company is a leader in the areas of Information and Communications, Automation and Control, Power, Transportation, Medical and Lighting. With its global headquarters in Munich, Siemens AG and its subsidiaries employ 417,000 people in 192 countries.

With its U.S. corporate headquarters in New York City, Siemens in the USA has sales of $16.6 billion and employs 65,000 people throughout all 50 states and Puerto Rico. Ten of Siemens' worldwide businesses are based in the United States. For more information on Siemens in the U.S.: www.usa.siemens.com.