What's good at the VW-cheat engine software update 1.2 TDI?

Munich, 14 December 2016

Most diesel models affected by the exhaust cheating were now converted from VW. But improved by the changes really NOx emissions? Deteriorate by any other values such as consumption or power? The Automobile Club ADAC has measured using the example of a VW Polo 1.2 TDI.

NOx: The software update works

The 75 HP three-cylinder diesel was offered by 2010 to the face lift in 2014 in the fifth generation Polo. The motor part (such as the affected 1.6 TDI and 2.0 TDI four cylinder) to the "cheat - series" EA189. This diesel realized that the car completed a cycle of Abgasmess and were on it, which resulted in extremely low NOx emissions. The ADAC examined a Polo 1.2 TDI now before and after the software update. Before that held the car Euro 5 certified the appropriate NOx limit value (180 milligrams per kilometre) is a bit surprising, after all, the cheat software was so programmed. After the conversion increased the value of nitric oxide easily, but with 132 milligrams per kilometre is still far below the limit. The exhaust gas cleaning works even without the cheating.

Consumption and performance virtually unchanged

It was exciting when evaluating the consumption measurement. Because in General, the simultaneous optimization of fuel thirst and nitric oxide emissions is a trade-off: A lean mixture leads to low consumption, but it is vice versa high NOx values, when the fat mixture. But consumption remained largely unchanged after the ADAC measurements. Even with the engine power, the tester noted no significant change.

But: The standard consumption is higher than specified

So everything in butter? Unfortunately, no. Because the measured consumption was and well above the manufacturer's instructions, as after the conversion. CO2 emissions revealed a divergence of 10.2 percent, the consumption exceeded the figures by 9.6 percent, where the tolerance is already deducted. It's not talking about the difference between standard and real consumption, because the ADAC also measured according to EU standard procedures on the rig. Where this over-consumption, furthermore the measurements provide no information.

At higher load marked NOx improvement

It is now a commonplace that the EU cycle little connection with reality has to do. Therefore the ADAC Maß also with realistic procedures, which are also the ADAC ECOTEST underlying: the WLTC cycle and the BAB130 cycle. Higher load conditions occur in both. Here resulted in a significant improvement of NOx emissions by up to 22.9 percent by retrofitting. Taking into account the measurement uncertainty of 2 per cent a small consumption increase from 0.5 to 2.7 percent is Polo VW depending on the cycle. Overall, the results are the results on the 2.0 TDI models, the ADAC investigated in June 2016: the conversion is for the environmental benefit. (sl)