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At the International Vienna Motor Symposium (24-25 April), Volkswagen has introduced the production version of the BlueTDI, a next-generation turbo diesel developed especially for the North American market. The common rail engine is based on the TDI engine, which was first introduced in Europe in 2007 with the Tiguan. This engine satisfies the Euro-5 standard that comes into effect in autumn 2009. In order to meet specific operating conditions in the U.S., this four-cylinder engine was redeveloped with internal engine modifications and a NOx trap. The engine will debut in the U.S. Jetta this summer.
A key aspect in the development of the BlueTDI (2.0 litre engine displacement, 103 kW/140 PS, 320 Nm) was the reduction of nitrogen oxide emissions (NOx); the American BIN5/LEV2 standards stipulate a nitrogen oxide limit of only 0.05 g/mile.
The internal engine changes include modifications to the design of the injection system of both the American and European TDI as well as the implementation of cylinder pressure sensors. This allows for a completely new type of cylinder pressure-based combustion control, which is both faster and tailored to each specific cylinder. Also new on-board: an optimised high-pressure injection pump. Another unique feature is the combination of a high-pressure exhaust gas recirculation system with additional low-pressure exhaust gas recirculation. This dual exhaust gas recirculation (dual circuit EGR) is an effective means of reducing nitrogen oxides in the engine. The dual circuit EGR system alone reduces NOx by up to 60 percent.
Outside of the engine, it is the NOx trap – connected downstream of the oxidation catalytic converter and the particle filter – that reduces nitrogen oxide to an absolute minimum. Implemented together, these measures reduce nitrogen oxide emissions by 90 percent.
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