Volkswagen has launched a new range of cleanest diesel engines (TDI). The TDI are characterized by extremely low nitrogen oxide emissions (NOx) and are thus many times below the Euro 6 NOx limit of 80 mg / km. The 310 kW (421 hp ) Touareg V8 TDI is one of the first Volkswagen’s emission control systems to filter out nitrogen oxides at this new level : it only emits between 10 and 20 mg / km. The NOx values were determined by RDE measurement (Real Driving Emissions ) in real road traffic; it was carried out by the independent British test and data specialist “Emissions Analytics”.
The RDE measurements defined by the European Union are extremely practical. They supplement the new WLTP test cycle (Worldwide Harmonized Light-Duty Vehicles Test Procedure) carried out on a roller test bench and thus under laboratory conditions with a test of emissions in real road traffic. In the case of the Touareg V8 TDI, these were carried out by “Emissions Analytics” in three German metropolitan areas – specifically synchronized with the real everyday life of Volkswagen customers. One test took place in topographically flat Lower Saxony, two further tests with height differences in the course of the route in Baden-Württemberg and Bavaria.
It is noteworthy that the all-wheel drive Touareg V8 TDI reliably undercut the NO x limit value in the tests regardless of the route, height differences and individual traffic conditions: in Lower Saxony the average was 10 mg / km, in Bavaria 13 g / km and in Baden-Württemberg 20 mg / km. On average of all three measurements, the NO x value of the Volkswagen was 14 mg / km. As outlined: The limit is 80 mg / km. Against this background, the Touareg V8 TDI sets important standards with its NO x values not only in the SUV premier class.
This positive result is made possible, among other things, by a multi-stage exhaust gas aftertreatment with a very large and high-quality coated NOx storage tank (2.3 liter volume) and an elaborately conditioned SCR system (Selective Catalytic Reduction). The SCR-Kat converts the NO x into harmless water vapor and nitrogen with the help of AdBlue (synthetic urea solution). Like all Volkswagen TDI models, the Touareg V8 TDI is also equipped with a diesel particulate filter.
In addition, the V8 TDI works particularly efficiently and economically due to numerous in-engine innovations. This includes a variable biturbo system: in part-load operation – for example in the city or on country roads – the V8 TDI, which is extremely torque-strong and therefore mostly driven at low speeds, is already running with just one turbocharger from 1,250 rpm with 900 Nm. This monoturbo operation lowers consumption and emissions. The second supercharger is only activated via an electric valve lift switchover at speeds of more than 2,200 rpm. The overall package is a neat thing: the Touareg V8 TDI confidently meets the Euro 6d-TEMP-EVAP-ISC emissions standard.
The TDI flagship is not the only Volkswagen whose NO x emissions are significantly better than the European limit: the new Golf and the current Passat are also part of this sustainable range with their new TDI engines from the four-cylinder EA288 Evo series. Further new models, whose TDI engines undercut the nitrogen oxide limit values with the lowest emissions, will follow.