Volkswagen’s CEO Martin Winterkorn has said he's ‘endlessly sorry’ that his company rigged the pollution control systems of millions of its diesel cars to show bogus emission levels during tests.

The company's US business chief, Michael Horn, admits VW "totally screwed up" and dramatically mislead the public and regulators. “Our company was dishonest with the EPA, and the California Air Resources Board and with all of you," Horn said at an auto industry event in New York.

But given the scale and nature of the deception first revealed last week, when the US Environmental Protection Agency announced that a secret 'defeat device' had been hidden in 500,000 VW-made vehicles in the US, and Volkswagen's admission today that the same trick was used on a total of 11 million cars worldwide, it likely will take far more than apologies to salvage VW's reputation and bottom line.

The company has lost more than a third of its value on stock markets in two days. It's facing billions of dollars in possible fines, likely lawsuits and possible criminal investigations.

It's recalling tens of thousands of cars in the US alone and shelving its new diesel models. And perhaps most importantly, it's losing the confidence of even its most loyal customers.

'We’ll see what happens over the next few days and weeks," said Pete LaFlamme of San Diego, who until last week was a proud owner of a VW-made Audi diesel. 'But right now, I would not want to continue purchasing VW or Audi cars.'

German-born Maximilian Auffhammer, a professor of international sustainable development at the University of California Berkeley and a life-long VW driver, feels the same.

"This does really change my perception of the company," Auffhammer says. "When the VW Beetle was released, the new one, it came with a flower! 'Look at us, the hippy spirit, the green sprit!' They came out with a diesel and told us how clean these cars are."

"(But) this was not an accident," Auffhammer says. Instead, he says, it was "a profit-seeking move to intentionally decieve both consumers and regulators. And it's going to cost them dearly."

The EPA says VW-made diesels sold since 2009 have been found to emit up to 40 times more smog-causing nitrogen oxide pollution than shows up in emissions tests, due to a specially-designed and cleverly-hidden mechanism that essentially turned pollution controls on when the cars were being tested, and off again when being driven normally.

Volkswagen has invested heavily in recent years in what it calls its 'clean diesel' technology, in an effort to rehabilitate a fuel that is powerful and efficient but notoriously dirty.

The revelations about the testing fraud, however, raise serious questions about the viability of that technology.

"Diesel seemed to be the 'have it all' solution for a while," Auffhammer said, speaking about manufacturers' and consumers' push for high-performing cars that are also clean and fuel-efficient. "But what this incident suggests is that diesel might not be the avenue we want to go after."

It also has put a bright spotlight on long-standing concerns that emissions and fuel-efficiency testing standards and practices in the US and Europe fall far short of achieving their goals of simulating performance in the real world.

Even without such direct trickery as VW has admitted to, "we know that the gap between the test results and the real world performance of vehicles is really wide," said Greg Archerof Brussels-based Transport and Environment, a group that campaigns for sustainable travel.

Archer believes the pollution testing regime in both the US and Europe is open to wide abuse.

"There’s something making sure that those laboratory results are particularly good," Archer said, which leads him to believe that other manufacturers could be caught in this scandal.

"In my experience, the only thing the vehicle manufacturers are concerned about is achieving their regulatory objectives at the cheapest possible cost. They don’t care whether their solution works on the road. They only want to pass the tests."

So far no other companies have been implicated in any deception. But European automaker stocks fell Tuesday amid signs regulators across the world will step up scrutiny of vehicle tests. The EPA said on Monday it would widen its investigation to other automakers, and French Finance Minister Michel Sapin said on Tuesday an EU-wide inquiry was needed too.

Archer and other activists are now calling for the testing regime in Europe and the US to be dramatically overhauled.

From PRI's The World ©2017 PRI