Porsche denies rumors of killing off diesel

According to insiders report, The Macan diesel stop-sale, because the German Transport ministry (KBA) found five potential emissions-cheating software codes in the engine’s management software

Porsche has moved to quell rumours that it has made the momentous decision to kill off all its diesel-powered models, effective immediately.

The rumours, kicked off by British magazines Autocar, Auto Express and Evo, insisted the German sportscar powerhouse was ending production of its diesel models in the face of a "cultural shift" from consumers.

Porsche has been embracing electrification and inching away from the compression fuel for a while, with the third generation Cayenne SUV launching with three petrol engines and a delayed diesel V6. More critically, it halted production of its Macan diesel on February 15. It has also stopped making the Panamera 4S diesel.

Yet the story is more complex than the British claim, with Porsche unwilling to voluntarily walk away from a third of its model mix in Western Europe, or about 15% globally.

The core problem lies in two areas: the new worldwide harmonised light vehicles test procedure (WLPT), real-world test procedures being phased in by the European Commission to replace the NEDC test cycle; and the recidivism of its diesel engine supplier, Audi.

The Macan diesel stop-sale, according to insiders, is because the German Transport ministry (KBA) found five potential emissions-cheating software codes in the engine’s management software. And the KBA’s a bit fed up with that sort of thing from the Volkswagen Group (VW).

In an enormous headache, German media reported that, this month, the KBA threatened to withdraw its type approval certificate for the Macan diesel due to its questionable software codes, which would have forced Porsche to buy back every single one of them it had sold in Europe. Porsche had been negotiating for a recall instead, but the KBA had been dragging its heels in validating Porsche’s (Audi’s, really) proposed software update.

And the walls closed in, so Porsche had to stop selling the car to stop the potential buy-back liability becoming any bigger and to throw the KBA a bone.

Porsche is no longer terribly amused by this sort of thing from Audi, its diesel engine supplier, and has been getting stroppier since "dieselgate" broke VW’s reputation wide open.

"[The recalled Cayenne V6 turbo-diesel] was the last thing we took straight from Audi and bolted in," Porsche technical director Michael Steiner said during an interview at the 2016 Paris motor show. "Back then it was more or less plug and play. It was in the platform we used and it was already developed. Today we could question it."

Porsche has done more than question it, though, and sued Audi last year for €200m in damages over the diesel-engine saga, and nobody at either company is talking about how that was concluded.

The second big issue is the WLPT, which every car maker admits is much, much harder to comply with than the new European driving cycle (NEDC). Every vehicle must be tested with every single engine and powertrain combination, plus every major trim level — and even every major option.

They aren’t the only ones to just give up claiming WLPT approval on a model too deep in its model cycle to recoup the added costs, especially if there’s any re-engineering work involved. BMW did the same last month with its M3 sedan, taking it off the market and waiting until its facelift.

The announcement also came on the heels of more bad news for diesel fans, with Mercedes-Benz under fire for alleged cheat codes in its diesel software. Germany’s Bild newspaper alleged the US department of justice found at least three software cheat codes in the Benz diesel management systems.

They include "Bit 13", to shut down selective catalytic reduction (SCR) after the cars emit 16g/km of NOx, "Bit 14" which it claims alters the SCR behaviour according to time and temperature parameters and something called "slipguard", which detects when the cars are on a rolling road, like in a laboratory.

The worst allegation is probably "Bit 15", which shuts down the SCR filter entirely after 26km of driving.

Benz denied the allegations, insisting Bild cherry-picked a very large dossier to hurt the company and its workers.

Benz also had to recall Vito vans to reflash the diesel emission-control software this month, while VW has piled up nearly 1,000 freshly-built Multivan T6s while they wait for software emissions clearance from Germany’s KBA.

It is a nervous week for Europe’s car makers, with Germany’s federal administrative court in Leipzig expected to rule on Thursday whether to ban pre-2015 diesel cars from German cities.

The case, brought by environmental group Umwelthilfe, is one of a raft of such cases across Germany, with others in Stuttgart, Düsseldorf and Munich as the country battles with airborne NOx levels well above the World Health Organisation’s recommended limit of 40μg/m³.

Munich’s average NOx value in 2017 was 78, Stuttgart’s was close behind at 73, Cologne’s hit 62 and major cities, such as Hamburg, Kiel, Düsseldorf, Heilbronn and Ludwigsburg, were all above 50.

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