Dieselgate: Why VW says it did nothing wrong

This is what we have learned so far.

Firstly, that Volkswagen is really sorry, but says it did nothing illegal in Europe.

Paul Willis, managing director of Volkswagen UK, appeared twice before the committee. The first time was on 12 October last year, less than a month after the German car manufacturer was caught cheating on emissions tests in the United States.

“First of all, I would like to apologise sincerely and unreservedly for the fact that Volkswagen has significantly let down its customers and the wider public over the findings of irregularities in some of the diesel-powered vehicles we produce,” Willis said.

But he also noted that the situation in the EU was different from that in the US, where Volkswagen had equipped its American diesel cars differently.

While Volkswagen has admitted to putting software in cars in the US that switched to a cleaner mode when under test conditions, it said that the test-recognising software with which European cars were equipped was not illegal under EU law.

According to non-governmental organisation Transport & Environment (T&E), Volkswagen and other car makers are using a loophole in the EU legislation.

Both in the US and the EU, test-rigging defeat devices are illegal, but according to T&E car manufacturers are using safety claims to get an exemption.

"Europe – as opposed to the US – has literally no provisions for: 1) manufacturers to disclose and justify where they use such exemptions; and 2) authorities to verify the legitimacy of such claims," one of the NGO's campaigners wrote in a blog post.

At a second hearing, in January, Willis brought his colleague Oliver Schmidt, an engineer at Volkswagen in Germany.

Schmidt said manufacturers were allowed to let their cars recognise they were being tested in Europe.

“European regulation gives you the ability to recognise that your vehicle is undergoing testing in order to have repeatability of emissions testing, so that every time you go through an emissions test you achieve the same result and are not bound to random circumstances,” noted the engineer.

“What you are not allowed to do is tamper with your emissions while recognising the test.”

Who dunnit?

But it is a big mystery who installed the software and why there were different approaches in the US and in the EU.

Willis said he thought a group of engineers – “very few people” - were responsible, and that nine employees had been suspended, but he did not know who they were.

The full picture should become apparent later this month, when the Volkswagen leadership receives the study it commissioned from US law firm Jones Day.

British MPs were puzzled and wondered why engineers would unilaterally decide to change the software without an order from higher up.

Committee chair Louise Ellman asked: “The same group, if they were responsible, took a decision to do one thing to deceive authorities in one place and another thing to deceive authorities in another place. Is that what you are saying?”

“At the moment it looks that way but, as Mr Willis pointed out, we have to wait for the details,” said Schmidt, who added later that Volkswagen did not tell the authorities what software it had put in its cars “because it was not mandated”.

This, and other statements, led some MPs to conclude that Volkswagen acted to the letter of the law but not the spirit.

Type approval

In a third hearing, late February, it emerged why.

Car manufacturers do not get certificates for each individual car they put on the EU market, but rather get a stamp of approval for a type – the so-called type approval.

In many cases, private companies carry out the tests on behalf of the national government's type approval authority. They are called technical services.

Representatives of two such technical services told the transport committee that optimising the test vehicle to get the best results is normal practice.

Tony Soper, technical specialist at a company called Millbrook, said cars would be tested with a higher tyre pressure, for example, which would “reduce the frictional losses”. Such practices are within the EU rules.

“If it is allowed within the emissions regulation, it is acceptable,” said Soper.

Soper's boss at Millbrook Group, Alex Burns, added: “Our responsibility is to ensure that the testing we do is in accordance with the regulations and the requirements of the type approval authority.”

He denied that there was a “cosy relationship” between companies like his and car manufacturers.

Burns said the type-approval authority, not his company, was responsible for finding defeat software.

Last October, the British transport secretary Patrick McLoughlin however reminded MPs that not all cars on the UK market were approved by the British authority, since “we operate in a single market”.

“A car can be tested in its own country of origin and, if that test is sufficient, it is type approved right across Europe,” said McLoughlin.

Difficult to find

But the head of the UK Vehicle Certification Agency (VCA) said the specific source code in the software responsible for test-recognition would have been “extremely difficult to find” even if experts had looked for it.

“If you hid a code in the engine-management system calibration, it is rather like hiding a virus in a computer software program,” said Paul Higgs, chief executive of the VCA.

“We would need a forensic analysis of the actual source code itself. Even then you would struggle to find where the actual defeat device was hidden.”

That is why, Higgs and McLoughlin argued, rather than trying to find a way to detect such defeat devices, they should be rendered useless by shifting the testing from a laboratory situation, to the real world.

These so-called real drive emissions tests will become operational next year.