Auto environmental list: Diesels are still not clean

In its new Car environmental list 2016 the VCS Verkehrs-Club der Schweiz recommends waiting before buying a diesel car. This is because the nitrogen oxide limit for diesels only applies to certification on the test bench. In real-world operation, however, diesel cars still emit several times more toxic nitrogen oxides (NOx).

However, thanks to the introduction of new test regulations, the so-called Real Drive Emission Tests (RDE tests), diesel models will soon be much cleaner. The most environmentally friendly way to drive in Germany continues to be with natural gas/biogas. As in the previous year, the three natural gas-powered cars VW eco up!, Skoda Citigo and Seat Mii are at the top of the Auto-Umweltliste 2016.

Rising sales of diesel cars

In conurbations and along busy roads, the immission limit value for NOx is not being complied with, and emissions have hardly fallen in recent years. The culprit is the increasing sales of diesel cars, which still emit ten times more nitrogen oxide than gasoline-powered vehicles. Although the permissible limit was lowered from 180 mg/km to 80 mg/km at the beginning of September 2014, under real-life conditions on the road diesels emit many times the pollutant load permitted in the test.

Around the exhaust emissions scandal of the last months, many independent pollutant measurements have been carried out on dozens of models. According to the EU Commission and confirmed by studies conducted by the Swiss Federal Laboratories for Materials Testing and Research Empa, NOx emissions from modern diesel passenger cars (Euro 6 standard) are on average five times higher in reality than the limit value of 80 mg/km applicable on the chassis dynamometer.

At the beginning of February, the EU Parliament decided to tighten the emission limits for NOx from September 2017. Based on these findings, the rating system of the Auto Environmental List will be adjusted with RDE tests until the introduction of the stricter test regulations and expects a realistic emission value of 400 mg/km (5 × 80 mg/km) with regard to NOx.

As a result, diesel models have temporarily almost completely disappeared from the ranking lists by vehicle class. The VCS's latest car environmental list therefore advises against buying these models with soon-to-be obsolete emission control technology. According to statements by carmakers, however, diesels that comply with the stricter emissions regulations and will therefore be significantly cleaner will be coming onto the market as early as the second quarter of 2016. These models can only be taken into account from the June update of the Auto-Environment list.

Natural gas/biogas cars unbeatable at the moment

The 33rd edition of the Auto-Umweltliste is also dominated by natural gas/biogas models. In addition to the three winning cars VW eco up!, Skoda Citigo and Seat Mii, the top ten ranking includes five other natural gas/biogas models. The once dominant hybrid cars are still represented by two models in the top ten.

There are two reasons for the superiority of natural gas/biogas cars: On the one hand, the combustion of natural gas produces less CO2 than gasoline or diesel engines, and on the other hand, around 20 percent climate-neutral biogas from waste recycling plants is added to Swiss natural gas. This is why natural gas cars also score better in the Auto Environmental List than hybrid cars.

Electric cars - only with renewable electricity

The electric car segment grew strongly last year. Of the purely battery-electric cars, 3257 units were put into service in 2015 (previous year: 1659). There was a marked increase in new registrations of plug-in hybrids from 827 (2014) to 2279 (2015) vehicles. By contrast, sales of "normal" hybrid models that cannot be charged from a power socket are stagnating. In 2014, sales were 6027 units, only marginally below the 2015 sales figures of 6191 passenger cars.

Experts continue to argue about the environmental compatibility of electric cars. The decisive factor in any case is the way in which the electricity is generated. A good environmental rating is only possible if the electricity for the drive is generated in a renewable way. Unfortunately, with a few exceptions, the industry's efforts to consistently use sustainable electricity are still not visible. The Auto Environmental List rates electric vehicles powered by green electricity in accordance with the Swiss "naturmade star" quality label in a separate compilation.