Strict new emissions tests disrupt Volkswagen production

German auto giant Volkswagen has warned it will have to halt production at its main Wolfsburg plant for several days next quarter as it adapts to rigorous new EU emissions tests.

"We must plan for interruptions to production in the third quarter," VW chief executive Herbert Diess told workers yesterday. He told staff to expect "closure days" in late summer and September.

New emissions standards known by the acronym WLTP -- short for Worldwide harmonised Light vehicles Test Procedure -- have already prompted VW subsidiary Porsche to suspend sales via its website, complaining of the "enormous burden" of the upcoming regulations.

From September 1, all cars sold in the European Union will have to be approved using the new scheme. The tests are meant to better mimic real-world driving conditions than past lab tests, giving a more accurate reading of the emissions of greenhouse gas carbon dioxide (CO2) and harmful nitrogen oxides (NOx).

The stricter emissions and fuel efficiency probes come after Volkswagen admitted in 2015 to installing software in millions of diesels designed to dupe tests, making the cars seem less polluting in the lab than they were on the road.

Some of the vehicles spewed up to 40 times more nitrogen oxide than legally allowed. Volkswagen said switching to the new regime required time-consuming testing, resulting in production bottlenecks.

But fellow German car makers BMW and Daimler said the change had not interrupted production at their plants. A spokesman for luxury brand BMW said the company had prepared for the switchover well in advance and that its delivery targets "remained unchanged".

Daimler's high-end subsidiary Mercedes-Benz meanwhile told the Handelsblatt financial daily that it wasn't expecting any "significant production gaps" because of the new test procedures.