| Volkswagen has introduced its cleanest ever TDI | | | | models below the Passat class. Nitrogen oxide is |
| engine. Initial test drives conducted by VW has | | | | absorbed like sponge which leads to a high level of |
| already showed promising results when the TDI | | | | efficiency. And in terms of the particle filter, the |
| engine was able to reduce nitrogen oxide. For | | | | system is regularly cleaned without the driver |
| Volkswagen's Jetta a new 2.0 liter commo9n rail | | | | noticing it. How? The engine management system |
| diesel engine with nitrogen oxide reservoir | | | | changes operation modes for a few seconds. For |
| catalytic converter was employed which | | | | Volkswagen's larger and heavier models, they will |
| conforms to the Californian emission standard | | | | feature the Selective Catalytic Reduction (SCR) |
| 'Tier 2/Bin 5'-considered to be the most strict in | | | | catalytic converter. The central component of the |
| the world. The first production of the TDI with | | | | SCR is an aqueous solution such as AdBlue which |
| nitrogen post treatment system will be made in | | | | is transported in an additional tank made from |
| 2008 in the US. The main objective of the TDI | | | | stainless steel or plastic. The aqueous solution is |
| engine is to reduce nitrogen oxide emission. | | | | also made up of 32.5% Urea which is continuously |
| Volkswagen's team of engineers in Wolfsburg is | | | | injected into the exhaust system in front of the |
| working on the development of the engine and | | | | SCR catalytic converter using a metering valve. |
| the use of new emission post-treatment | | | | The quantity of the aqueous solution is made |
| technology. They have already achieved 90% less | | | | according to the gas emission stream. The urea |
| nitrogen oxide emissions. The said drastic | | | | solution that is mixed with the aqueous solution is |
| reduction was needed in order to comply with the | | | | finely atomized by a grille and is converted in hot |
| Tier 2/Bin 5 standard which applies to California | | | | exhaust gas into ammonia before it reaches the |
| and four other states in the north-east of | | | | catalytic converter. The ammonia then reacts |
| America namely: Massachusetts, New York, | | | | with the nitrogen oxide in the catalytic converter |
| Vermont and Maine. ---This norm limits Nox | | | | and separates in into water and nitrogen. The |
| emissions to 70mg per mile. And in order to | | | | ammonia produce is not like the ordinary ammonia |
| comply with this standard VW has decided to | | | | in the sense that it is non-toxic, odorless and |
| develop a completely new emission treatment | | | | biodegradable. Volkswagen also intends to install |
| technology. Volkswagen was able to develop two | | | | the additional tank so that the car may be driven |
| new systems connected to the oxidation catalytic | | | | without the need for maintenance between |
| converter and the particle filter in the exhaust | | | | services. According to US regulations the |
| system. The new Nox reservoir catalytic | | | | complete system should be functional for at least |
| converter technology is currently tested for car | | | | 150,000 miles. |