After a probe demanded by the Japanese authorities, four diesel models made by local automakers have been found emitting much higher NOx than in the lab, the World Street Journal reports.
Volkswagen’s cheating saga triggered a global storm over diesel powered cars and many regulators have already started to take a closer look at vehicles’ emissions levels. The French authorities, for example, have found out some NOx irregularities on models from Renault, Ford and Mercedes-Benz. Now, a new report shows that some diesels made by Toyota, Nissan and Mitsubishi are over-polluting, the World Street Journal says. Some tests ordered by the Japanese regulators revealed that Toyota Hiace van, Land Cruiser Prado and Nissan X-Trail emitted up to 10 times over the legal limits, while The Mitsubishi Delica D:5 had 5 times higher NOx than in laboratory tests. However, there were no cheating devices fitted on those diesel models and the automakers did not breach any rules, officials said, as all cars have previously passed the emissions approval tests.
In Japan, diesels must pass 20-minute laboratory checks before going on the market. According to the transport ministry, the big emissions gap was because the real-world assessment was conducted during cold weather, causing the engine software to enter in “defense” mode and to cut the exhaust gas recirculation system. Toyota said it also sold some diesel Hiace vans in Hong Kong, Singapore, Chile and Russia. Nissan said different versions of the diesel X-Trail were sold mainly in Europe, while Mitsubishi said the Delica was a Japan-only model. The findings prompted the ministry to consider the possibility of introducing real-road tests for diesels before going on sale.