Volkswagen is to introduce 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, which was first introduced in Europe in 2007 with the Tiguan. This engine already 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.
Five U.S. states, including California, currently have the strictest emissions standards in the world (BIN5/LEV2). In spite of variations in fuel quality, which are more pronounced in the U.S. than in Europe, the new BlueTDI meets these emissions standards. The engine will debut in the U.S. Jetta this summer.
The Jetta BlueTDI will debut as one of the cleanest and most economic cars of its class in the world. In the run-up to the Vienna Motor Symposium, where it will be launched, Dr. Ing. Jens Hadler, Director of Volkswagen Powertrain Development comments, “High fuel prices and a dramatic change in environmental consciousness means that diesel is becoming more and more attractive for American drivers every day. This is why many customers, especially in California, have been waiting for a super-clean diesel like our BlueTDI. I think this engine will help the diesel get its big break in America because it consumes so little and yet can go such long distances on a single fill-up. And in a country as big as the United States, this is a priceless advantage. On the highway, for example, this engine can reach up to 60 miles per gallon. This is an improvement of 12 percent over its predecessor, which had a lower capacity and higher emissions.”
A key aspect in the development of the 2.0 litre BlueTDI was the reduction of nitrogen oxide emissions (NOx); the American BIN5/LEV2 standards stipulate a nitrogen oxide limit of only 0.05 g/mile. This limit, and the general reduction of raw emissions, has been met by using internal engine modifications, some of which are unique worldwide, and implementing the maintenance-free NOx trap.
These 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.
The BlueTDI will debut in the Jetta mid-year in North America.