German OEMs – namely BMW, Mercedes, Audi and VW – are criticising Toyota’s D-CAT diesel engine, saying that it is ineffective after 5,000-8,000km, reports Automobilwoche.

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The D-CAT combines Toyota’s Diesel Particulate NOx Reduction System (DPNR) with a diesel particulate filter. It has been fitted on the Avensis since 2003.
 
Toyota claims that the technology exceeds Euro 4 norms and has the potential to meet proposed Euro 5 emission limits, reports Automobilwoche.


Automobilwoche has learnt that the OEMs have been conducting durability tests and found that after a short time – possibly as little as 5,000 km, NOx reduction starts to decline. This means that it would no longer meet Euro 4 limits.


The German OEMs have made the European Commission aware of the problem, according to the report. They are afraid that Toyota might persuade the Commission that a DeNOx catalyst is the way forward and that this will influence the level at which NOx emission limits are set for future Euro 5 norms.


If, once in place, the Euro 5 limits cannot reliably be met with a DeNOx catalyst after all, Toyota will cash in by pushing its hybrid technology, suggests one OEM quoted in the article.


Toyota is continuously developing its D-CAT system, according to a later article in the same publication. Its new D-4D Clear Power 4-cylinder engine, which will appear in the summer of this year, will exceed current DeNOx performance.

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