For the second time in as many months, Vicente Franco will be speaking in the European Parliament building in Brussels about his organisation's research – because it triggered the Volkswagen emissions-test scandal.

Franco, of the International Council on Clean Transportation (ICCT), is due to appear as a witness at the parliament's “dieselgate” inquiry committee on Tuesday (19 April). Franco's colleagues at the ICCT were the first to raise problems with Volkswagen's diesel cars, but the Berlin-based Spaniard has been involved in other emissions research that may interest MEPs.

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The previous time Franco gave a presentation about his non-profit research group, on 1 March, it was held in a small room hidden between MEPs' offices on the fifth floor.

At a briefing organised by Spanish Green MEP Jordi Sebastia, the engineer told journalists that the ICCT was not actually looking for the software that allowed Volkswagen to cheat on emissions tests in the US.

“What we wanted to show the European authorities, is that diesel could be made clean with better regulation. And the example we thought was the best was the US cars,” he said.

But what they found instead was a larger discrepancy between the emissions levels when Volkswagens were tested on the road, compared with laboratory test results.

This finding led the United States Environmental Protection Agency (EPA) to investigate, the results of which were announced in September last year: Volkswagen had cheated.

But even without the cheating, it was already public knowledge that real emissions were often much higher than the test results.

A European problem

Franco emphasised that although the findings were made in the US, excessively high emissions from diesel cars were actually “a European problem”. Pointing to new passenger car registrations in 2014, he noted that just 1 percent of US cars were diesel compared with 53 percent of European cars.

But the emission limits for nitric oxide and nitrogen dioxide (lethal pollutants known together as NOx) in the US were half of those in the EU, Franco noted. This is why US diesel cars were equipped with better NOx-neutralising technology than those in the EU.

“This is a question of economics. If the regulatory framework in the US is so stringent that it forces the adoption of best technologies. The manufacturers simply did that,” said Franco.

“They mounted more technology in order to meet the standard. In Europe this was not required, manufacturers were able to meet the standard with less technology, they were able to get away with worse on-road performance, and that’s what we got.”

He added that the EPA in the US had much greater power and resources than its European counterpart, which itself has limited powers compared with national authorities of member states.

“They can test randomly, they can do everything. And they are fiercely independent,” he said about the EPA.

But, Franco noted, there was reason for optimism: the recent EU commission's proposal to overhaul the system for approving car types.

“What’s being proposed in Europe is not a fundamental change. There will not be a central authority,” he said, adding that the proposal would not introduce an American-style system.

“But having said that, it’s absolutely an improvement and we’re all for it.”

Joint Research Centre

Tuesday's hearing starts at 15:00 and will first feature Delilah Al Khudhairy of the EU's Joint Research Centre (JRC). The European Commission's in-house science service warned in a report published in 2013 that it was possible that car companies were using defeat devices.

The EP committee had originally wanted the JRC's top boss to show up, but according to a spokeswoman at the JRC, its director-general had "a long-planned external commitment".

The spokeswoman told this website that Al Khudhairy "has been closely following the emissions dossier since she was appointed in September 2015".