BMW stock tumbles after report of high emissions Volkswagen scandal prompts closer look at other automakers as BMW denies any manipulative actions

Nathan Bomey | USA TODAY

Show Caption Hide Caption Germany to begin roadside tests of non-VW diesels The German government will begin roadside testing of diesel fuel vehicles in the wake of the Volkswagen emission scandal as a report that BMW's X3 xDrive 20d SUV emitted as much as 11 times the European limit for air pollution.

A sudden wave of scrutiny over emissions threatened to engulf BMW after a German magazine reported Thursday that one of the luxury automaker's diesel vehicles emitted 11 times the amount of nitrogen oxides acceptable in Europe.

The German automaker's shares tumbled about 5% Thursday following Auto Bild magazine's report that the International Council on Clean Transportation had discovered curiously high emissions on the BMW X3 crossover vehicle.

BMW issued a forceful statement denying any wrongdoing, saying in an email to USA TODAY that it "does not manipulate or rig any emissions tests."

"We observe the legal requirements in each country and adhere to all local testing requirements," BMW said. "When it comes to our vehicles, there is no difference in the treatment of exhaust emissions whether they are on rollers (e.g., test bench situation) or on the road."

The news comes after an ICCT investigation conducted in cooperation with West Virginia University researchers uncovered irregularities in the emissions performance of Volkswagen diesel cars.

That prompted a U.S. Environmental Protection Agency investigation that caused Volkswagen to admit it had rigged 11 million cars worldwide with cheating software, a scandal that has crushed the German automaker's stock, severely damaged the VW brand and triggered costs of more than $7 billion.

To be sure, while Volkswagen intentionally misled regulators by installing a so-called "defeat device" on diesel vehicles, it's far from clear whether BMW or other automakers have used similarly deceptive software.

BMW said it is "not familiar with the test mentioned by Auto Bild" but will ask ICCT "for clarification of the test they carried out."

ICCT research has previously suggested that excessive nitrogen oxide emissions — which can exacerbate respiratory conditions such as asthma — may not be exclusive to Volkswagen.

In a report earlier this month, ICCT said that on-road testing of 32 European diesel cars from 10 automakers found that the average vehicle was generating nitrogen oxide emissions at twice the regulatory limit.

Some "manufacturers seem to be focusing on meeting emission limits over the current test cycle while neglecting real-world operating conditions," ICCT study co-author Vicente Franco said in a statement.

Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.