BY NOW, everybody knows Volkswagen got caught cheating on emissions tests, in a blatant, illegal move that saved it, and cost it, billions of euros.

Now, embarrassed that the cheat was caught in the US and not in Germany or even in Europe, new cars are being tested far more stringently.

While European governments have yet to uncover evidence of anybody else using a VW-style “defeat” device, many of its rivals are not coming up smelling of roses.

The inescapable conclusion to draw from the closing-the-door-after-the-horse-has-bolted testing and indignation from European Union (EU) member states is that the entire car industry cheats.

Most of the cheating that goes on is not illegal, like VW’s software fiddle (that turned on a car’s maximum NOx-cleaning systems when it figured out it was in a laboratory, but did not bother when it was on a public road), but it is every bit as widespread and has the exact same intention.

Whether it is legal or not, a lot of what has been going on is unquestionably wrong.

The car companies have argued they have been using the grey-area margins allowed for in the EU’s outdated New European Driving Cycle (NEDC) test, but the reality is they have been playing games that any outsider would tell you are unethical.

Mercedes-Benz, for example, had its all-new four-cylinder turbodiesel C-Class fail miserably in an independent real-world emissions test in The Netherlands two months ago. It did so again in a 93-car test, costing more than €1m, in Germany, but so did 16 others.

Questions about the failures so incensed Mercedes-Benz’s public relations team that one of its operatives told a motoring journalist to “f**k off”, and accused him of attempting to lump it with VW to affect parent company Daimler’s share price.

But this is what happened, and you can be the judge: Mercedes-Benz fits three types of NOx-cleaning technology to its diesel-powered cars, one of which is Exhaust Gas Recirculation (EGR), which diverts exhaust gases back into the combustion chamber to burn off the nastiest stuff. You know, the NOx that causes tens of thousands of deaths a year.

Except the Benz technology does not always do that. At temperatures below 10°C, it just switches the system off completely (the Dutch test was conducted at six degrees).

It does this, Benz insists, because the EU rules allow it to take measures under “unusual environmental conditions” to guarantee the EGR is still effective after 160,000km.

In Europe, at least half of the population can expect the temperature to fall below 10°C for about four months of the year, yet Mercedes defines it as “unusual”. If the world’s oldest car company is incapable of engineering a car to operate effectively for a third of the year, it can hardly claim “The Best Or Nothing” as a slogan, can it?

If you think that’s bad, they do the same thing over at Opel, but lift the cut-off temperature to 17°C, which covers about nine months of the year. Er, what?

The German government pulled in all 17 car makers when it twigged to the ruse, and used its upcoming electric-car rebate as leverage to persuade Mercedes, Porsche, Opel, VW and Audi (not BMW, which is looking increasingly like a clean-skin) to voluntarily recall 630,000 cars across the country to fix it.

Even then, the car companies insisted they were in full compliance with the law, which makes you wonder why they were in such a hurry to recall the cars. But not as much as you wonder what’s going through the heads of the 12 companies (Jeep, Hyundai, Kia, Mazda, Honda, Mitsubishi, Renault, Nissan, Citroen, Peugeot, Fiat and Volvo) who ignored the government’s suggestion.

Daimler’s share price fell 9% after this hiccup and it is being hauled before the US justice department to explain its emissions certification processes.

Peugeot, meanwhile, joined Renault on the list of car companies raided by the French government’s fraud squad over the differences in its laboratory and real-world test figures. Its share price fell nearly 3%.

VW arrived at an expensive, expansive settlement with the US government over Dieselgate, promising to fix or buy back its 482,000 cheater cars in the US and setting aside €17bn to clean up the mess globally.

In the same week, Mitsubishi was discovered (by Nissan, of all its possible interrogators) using cheater high tyre pressures to illegally lower fuel consumption in laboratory tests — for the past 25 years.

It seems unavoidably obvious those emissions laws are being treated with contempt and that the whole thing is a sport waiting to be gamed for a profit.

As all this was going on, the European Automobile Manufacturers Association insisted that all the vehicles implicated in the 17-brand German investigation were “compliant with current regulatory requirements” and that the NEDC test the real-world figures were deviating from was an obsolete measurement. “This is why we have been advocating for many years for an updated laboratory test — WLTP — as well as an additional new test to measure pollutant emissions on the road (the Real Driving Emissions, or RDE test),” association secretary-general Erik Jonnaert said.

“These results show again that we now need to move forward with the new testing conditions in order to bridge the gap with the lab test,” he said. “RDE represents a tremendous effort for Europe’s car manufacturers, both in terms of investments and production, but our industry will take up this challenge.”

That is all lovely, though it is thoroughly disingenuous.

Sure, they have advocated for it, but Reuters has reported that the association’s chairman (and the boss of Renault-Nissan) Carlos Ghosn does not believe any significant progress can be made on NOx before 2019 and that, even then, the association would prefer to raise the EU limit by 70% (or up to more than three times the US limit), rather than lower it.

It is also massively disingenuous because while they want the new test in place, they only want it on the terms that suit them (why else do you suppose it has been delayed so often?) and they have demanded some form of compensation for the current fiddles any such real-world test would rob them of.

Most of these legal “cheats” are coming to light only because the car makers are admitting to things that will be banned under either the WLPT or the RDE, in an effort to pry some sort of numerical compensation out of the EU.

Greg Archer, the vehicles programme manager at nonprofit lobby group Transport and Environment, is not surprised. He also has a long list of legal “cheats”, just like the temperature one, that are only just coming to light and which explain why there is such a huge difference between NEDC laboratory consumption figures and fleet data, which suggests real-world fuel economy and emissions have not actually improved in decades.

Archer arrives at his lab-to-real world differential figures by looking through the European Commission’s correlation exercises, designed to ease the shock of the switch from the lab-based NEDC to the real-world tests.

“The manufacturers have been saying that ‘we do this and that in the NEDC but we are not allowed to do these things in the real-world test but we want to be given credit for them’. If you add all these things up you get to a gap of 40% to 45%. The companies with the lowest gap in CO2 to real-world tests are Fiat and Toyota, consistently, I suspect only because they don’t make use of every flexibility offered.”

Companies that insisted, following the VW scandal, that their NOx testing was legitimate have shown huge discrepancies between their test figures for CO2 and the real-world figures. Archer claimed last year that the gap was biggest at Mercedes-Benz, at well over 50%.

“We don’t know enough flexibilities in the test to make them add up to 50%, so something else is going on,” he noted four months ago, presciently predicting the temperature-control scandal the company is now embroiled in.

“I am not saying that means there is a default device. But they need to explain how they achieved such low levels in the laboratory and got more than 50% more in the real-world test. How can they be producing such low overall CO2 figures in a laboratory but not when these vehicles are operating on the road?

“Where are they designed to operate if not on the road? From what we know about the different ways manufacturers manipulate the tests, they should not be able to get more than 40% to 45% difference between test and real-world figures.”

If all of this isn’t enough to get the attention of the German car makers, this last part might: the Deutsche Umwelthilfe environmental group has sued the city of Stuttgart to get diesel-powered cars banned from the city, because Stuttgart, the home of Mercedes-Benz, Porsche and Bosch, has the highest airborne NOx pollution levels in Europe.