Motor Mouth: Dieselgate returns—this time it’s not Volkswagen

Some 11 years after emissions-spewing diesels first scandalized the world, we’re still sorting through the mess

The United Kingdom’s High Court recently ruled against a whole slew of new “Dieselgate”-like accusations in favour of Mercedes-Benz, Renault, Nissan, Ford, and Peugeot and Citroën. Though the ruling, by Lady Justice Cockerill, ran to a whopping 369 pages, the crux of the matter seemed to centre around her contention that the cars exonerated were not, in fact, being manipulated by a prohibited “defeat device.” Now, to anyone who’s followed these seemingly endless Dieselgate recriminations — it started way back in September of 2015! —

defeat devices are a well-known miscreant. To those who’ve forgotten, Volkswagen was found to have created a software stratagem for some of its diesels — mostly 2.0-litre TDIs powering Golfs, Jettas, and Passats, as well as Beetles — that emitted illegal amounts of nitrogen oxides in regular use, but could, when the software detected that an official emissions test was being conducted, dial back its NOx output to legal standards. The result was perhaps the biggest automotive-related scandal of the century.

VW was fined billions — well over USD$30 billion over the years of litigation, settlements, and penalties — in both the European Union and the United States. Countless cars were recalled, and, to a significant degree, the success of the modern EV revolution owes much to diesels falling out of favour as a result of the controversy. Here in Canada, owners of afflicted VeeDubs were offered buy-backs or trade-ins, as well as upgrades that rectified the excess emissions, and all owners, regardless of their choice of solution, received a cash settlement.

Less reported is that diesels from other marques — Fiat-Chrysler Automobiles (now Stellantis) in the U.S.; and BMW and Opel in the E.U. as well as others — were also accused of similar transgressions. This recent case involving some Ford, Nissan-Renault, Mercedes-Benz, and Peugeot-Citroën vehicles, then, is just the latest — and, barring appeals, hopefully the last — major action against excessively-polluting diesels. What’s interesting about the U.K. case, which saw the majority of automakers exonerated — one Mercedes model, as well as a few Peugeots and Citroëns, were found “guilty” — is that the judgment came down to the High Court’s definition of a defeat device.

According to the judge, it was all about intent, her ruling stating that “in the majority of instances, the Court found that the relevant strategy did not constitute a prohibited defeat device,” while she pondered whether “for a defeat device to be found, does there need to be an intention to cause the emissions control system to operate differently when it senses it is being tested.” In non-legalese, it wasn’t enough to find fault with the manufacturers simply because their cars polluted more than was allowed. This, of course, has enraged the lawyers representing the 1.6 million British vehicle owners with these ‘afflicted’ diesels who claimed that all their cars contained devices which were also “prohibited defeat” or “cheat” devices.

One law firm, Leigh Day, contended that Brexit was at least partially to blame for this adverse ruling. According to its solicitors, “the judge decided post-Brexit not to follow several key decisions of the Grand Chamber of the Court of Justice of the European Union (CJEU).” And, indeed the CJEU’s definition of a “prohibited defeat device” mentions nothing regarding intent, rather specifying that any piece of hardware or software that senses any parameters — temperature, vehicle speed, engine speed, etc. — for the purposes of modulating or deactivating any emissions control is considered illegal.

That Grand Chamber’s broad definition of a defeat device requires no specific intent to deceive regulatory bodies, only that the cars involved do ‘blow’ over the limit. I’ve got to admit that, at first blush — and, by “first blush,” I mean reading the various articles covering the case — the judge’s requirement of intent to find culpability in an automaker’s failure to meet the emissions standards seemed odd. On reading the full 369 pages of her ruling, however, it quickly becomes obvious that Lady Justice Cockerill is extremely well-versed in the subject of automotive emissions systems, and her definition of what constitutes a defeat device seemingly more practical than that which the complainants’ lawyers were hoping for.

For instance, in her ruling she notes right at the outset “that there is no allegation that any of the [vehicles] contained a device which is the same as the VW PDD at the centre of Dieselgate.” Another specific key point that’s gone largely unreported — presumably because those reporting on the trial don’t understand the subject nearly as well as Judge Cockerill — is that the claimants allege that any “device that reduces the Exhaust Gas Recirculation (‘EGR’) rate by a fraction of a percentage point from the level at which it would operate during the test, for just a moment or two, and which operates only at -10oC ambient temperature, is a [prohibited defeat device].”

By her reckoning — she later points out that actual emissions testing is conducted strictly between 20oC and 30oC — this would mean “that every single Euro 5 and Euro 6 vehicle produced by every single manufacturer contained a PDD.” At this point, it might be worth reminding readers that Volkswagen’s diesels were emitting up to 40 times the legal amount of NOx pollutants any time they weren’t being tested, which, for the vast preponderance of cars, was all the time. It’s also worth noting that Cockerill’s ruling spends much time parsing the legalese of “normal” and “typical” automobile operation as it’s obvious she and the complainants’ lawyers sparred over whether a defeat device only included technology that specifically singled out testing conditions or whether it should also include any algorithm that allowed for modestly increased emissions at the extremes of the temperature, altitude, and loading a diesel car might see.

It’s also worth noting that a goodly portion of her ruling is devoted to an almost encyclopedic description of how diesels function, how compression-ignition emissions work, and a bountiful description of the various mitigation systems — Exhaust Gas Recirculation (EGR), Lean NOx Traps (LNT), and Selective Catalytic Reductions (SCR) systems — designed to reduce tailpipe emissions. Now, I have no way of knowing if the judge wrote every word describing the effect of Diesel Exhaust Fluid (DEF), or her judgment that Ambient Air Temperature (AAT) is, “generally speaking,” 5oC less than what the Intake Air Temperature (IAT) sensor is reading, but if she even understands all that is written in her “Approved Judgement,” she could easily find a second career teaching at any trade school in the world.

Hell, she’d be the dean. Which is why, after the appeals are over and done with, I suspect her ruling will stand. Notwithstanding the fact that Judge Cockerill did determine that one 2015 model Mercedes did employ a bona fide defeat device — her explanation of which would pass muster in any engineering PhD thesis defence — the claimants appear to be trying to piggyback Dieselgate-era controversy into their complaints, which are, frankly, not nearly as egregious as what Volkswagen did with its actual cheats.

Nor do the faults of the majority of cars listed in the lawsuit seem premeditated specifically to circumvent emissions testing. So, for now, most of those 1.6 million Mercedes, Nissan, Ford, Renault, and Peugeot-Citroën owners will not be recompensed. Actually, the number of complainants going unsatisfied could go even higher, since this was just the first of several similar trials.

And, absent a revised definition of a defeat device on appeal, owners of diesel-powered Opels, Vauxhalls, Porsches, Jaguars, Land Rovers, BMWs, various FCA products, as well as Suzukis, Toyotas, Mazdas, and others — who were scheduled to be heard in England’s High Court on the same matter starting in October — will likely also go unsatisfied. Whatever the outcome of further cases or any appeal to Cockerill’s judgment, it’s absolutely amazing that, almost 11 years since Dieselgate first reared its ugly, emission-spewing head, justice is still being delayed. Sign up for our newsletter Blind-Spot Monitor and follow our social channels on X, Tiktok and LinkedIn to stay up to date on the latest automotive news, reviews, car culture, and vehicle shopping advice.