Press Release
Faster and lighter: In practice, the new piezoelectric technology offers many benefits: The electronically actuated piezoelectric actuator switches five times faster than a conventional solenoid valve. It is directly integrated in the injector, which means the movement is transferred directly onto the nozzle needle without a mechanical element and the moved mass on the nozzle needle is reduced by 75 percent from 16 grams to only 4 grams now. In addition, piezoelectric technology doubles the nozzle needle speed compared to solenoid valves. Injection itself is performed using a 7-hole nozzle; it promotes homogenous fuel distribution throughout the combustion chamber and thereby makes a contribution to reduced emissions thanks to the associated greater combustion efficiency.Four injections per cycle: Thanks to these technical provisions, it is possible to vary the number of injection procedures to ideally match the particular operating conditions. In the case of the new V6 TDI, Volkswagen uses up to four injections per combustion cycle in total: In addition to the main injection, there is a double pre-injection in the low rpm range and a single pre-injection in the medium rpm range. In addition, there is a single post-injection up to approx. 2500 rpm. On the one hand, this injection sequence ensures optimum emissions behaviour while on the other hand combustion is smoother and therefore the engine acoustics are extremely comfortable. The V6 TDI sets new standards in this respect and can scarcely be heard as a diesel engine even inside the Touareg. Instead, the engine acoustics just like its smooth running are entirely comparable to those of a six-cylinder petrol engine.
Centrally integrated turbocharger, two intercoolers: The turbocharger is located centrally in the V-angle of the engine so as to achieve optimum economy of space. To enable the turbo to operate with the best possible efficiency, the temperature of the induction air is effectively reduced by two intercoolers connected in parallel with minimum pressure loss. The variable turbine geometry of the turbocharger is controlled by an electrical actuator in the new V6 TDI. It means the guide blades are adjusted more quickly and more exactly. As a result, the charge air pressure is built up significantly faster, particularly at low revs, resulting in improved response characteristics. The optimised blade shape of the compressor and turbine wheel effectively promotes this direct conversion.
Variable induction tract: Additionally, infinitely variable swirl flaps are integrated in the induction tract. They adapt the air movement to the particular engine speed and load. Background: A high level of swirl at low engine load also helps to optimise combustion as does, conversely, low swirl at high engine load. In practice, this means a closed duct at low load increases swirl whereas an open duct at high load makes it possible to achieve a high level of cylinder charging.
Exhaust gas recirculation: The new V6 TDI with its very highly developed injection technology is characterised by particularly low pollution emissions; pollutants are reduced to a large extent as part of the combustion process. The remainder of the exhaust gases is rendered inoffensive in subsequent processes. Controlled exhaust gas recirculation promotes this: The exhaust manifold has double walls (with air gap insulation) so the exhaust gases can be sent for exhaust gas post-treatment without noticeable heat losses. The exhaust gas recirculation itself, in contrast, requires effective cooling so as to make real inroads into NOx and particulate emissions, for example. To achieve this, the exhaust gas passes through an exhaust gas recirculation cooler with water through-flow that is controlled according to temperature and load. This cooler is located within the inner angle of the engine??????????????????????????????????????s V, thereby further optimising the economy of space in the engine. During the cold-start phase, the exhaust gases are passed through a bypass duct to build up pressure ahead of the cooler. This enables the catalytic converters to reach their ideal operating temperature more rapidly. Once the engine and the catalytic converters are up to temperature, the exhaust gas flow enters the EGR cooling zone directly.
Zero-maintenance diesel particulate filter as standard
Diesel particulate filter: The Touareg V6 TDI is equipped with a diesel particulate filter as standard. This temporarily stores and eliminates the diesel soot before it is emitted into the atmosphere with the exhaust gases. As a rule, the effect of diesel particulate filters supplements that of oxidation catalysts that have been used for a long time now.Catalytic converter and DPF: The exhaust gas is cleaned using a primary catalytic converter located close to the engine (near the turbocharger) and the main catalytic converter in the underbody. Furthermore, soot particles are separated out by a diesel particulate filter that is installed as standard.
In general, diesel particulate filters are used for capturing and eliminating the diesel soot before it is emitted into the atmosphere with the exhaust gases. In the Touareg V6 TDI, the system used is an advanced, state-of-the-art design. The catalysed soot filter (CSF) employs a filter coating containing precious metal that operates in two ways. During passive regeneration, the soot stored in the catalytic converter is slowly and carefully converted into CO2. This process takes place in a temperature range from 350 to 500 ????????????????????C and continues without requiring any special intervention, particularly when the vehicle is predominantly used for motorway driving. Only during longer periods under low load (primarily in urban traffic), the exhaust temperature is actively increased to about 600 ????????????????????C every 1000 to 1200 kilometres for additional filter regeneration. The particles stored in the filter are burned off at this temperature.
