Benz backs diesel future

Mercedes-Benz has reiterated its commitment to diesel engines even as it becomes ensnared in the widening emissions scandal triggered by the Volkswagen dieselgate affair.

But it has also admitted its new modular inline engine family gives it the option of quickly switching production from diesel to petrol if buyer patterns change.

The company is defending a class action lawsuit in the United States in the wake of revelations the emissions treatment system in a range of its Bluetec turbo-diesels shut down when temperatures dropped below 10 degrees Celsius, allowing harmful Nitrogen Oxides (NOx) emissions far above EU and US EPA limits.

Benz has also been asked by the US Department of Justice to investigate its emissions certification process for vehicles and has been part of a voluntary recalls in Germany and UK to re-code diesel engine software that relates to the issue.

According to European reports manufacturers exploited a “legal loophole” to shut down the systems. The strategy drew a stinging rebuke from the European business newspaper, The Financial Times, in an editorial last week.

“It is absurd that manufacturers still argue that the 'exceptional circumstances' in which they can turn off emissions control systems to protect a car’s engine should include routine situations such as weather barely below room temperature.”

But at a future drivetrains media briefing in Stuttgart last where the new OM 654 turbo-diesel engine was one of the star attractions, Benz product strategy chief Wilko Stark insisted the luxury brand’s commitment to compression ignition technology was undiminished.

“The short answer is yes for one simple reason,” he told motoring.com.au. “What is currently going on in the discussion in public is nothing to do with this new diesel engine because the new diesel engine does meet all regulation requirements, even what is coming up in 2018 to 2020.

“So we really have to separate this discussion. We really strongly believe in diesel technology because it has such a big benefit regarding carbon-dioxide and it’s a big big lever for the overall fuel consumption targets in Europe.”

The OM 654 is the first powerplant from the new modular family that will also spawn petrol four-cylinder and inline petrol and diesel six-cylinder engines. The sixes will launch as part of a late 2017 S-Class update and gradually replace V6s across the Benz range.

Mercedes-Benz powertrain vice-president Bernhard Heil confirmed to motoring.com.au at the briefing the new engine’s emission treatment system stayed on at low temperature. He said its compliance with regulations had been tested by DEKRA, the independent German vehicle inspection company.

“Basically we did a lot of improvements on that engine and all what we measured and all what the DEKRA people measured was that even in minus Celsius temperatures the efficiency of the after treatment system is given so that you are completely in line with those limits to come to achieve those conformity factors.”

Asked if that meant the emissions treatment systems stayed on at low temperatures, Heil said: “Yes”.

But when Heil was asked if Benz would address the emissions shutdown issues with an engineering fix for the diesel engines currently in service his PR minder intervened.

“Basically we have communicated what we are going to do with our current engines in the market,” the PR said. “We have announced a voluntary service update.”

motoring.com.au was promised further details of the work performed under the update but these were not supplied despite a follow-up request.

The PR also cited the US lawsuit as a reason not to discuss the after-treatment issues: “Please understand we do not comment on the case because they have asked us not communicate. We would like to do the case and get the issue resolved. We have nothing to hide.”

Stark was slightly more forthcoming about fixing the current diesels: “We are going to address that,” he told motoring.com.au before also being shut down by his minder.

Stark admitted Benz was still unsure just what the fall-out from the various emissions scandals now emerging would have on diesel sales.

“This is a big, big question,” Stark said. “I think the question is ‘does it have any negative impact on the mix of diesel engines in total?’

“This is a question still to be answered, no-one knows yet. But we have the big, big benefit regarding our production system and our new engines that we have our diesel engine and our new petrol engine.

“Our diesel engines in four-cylinder and six-cylinder have more or less much the same concept, so we share a lot the same parts.

“And therefore we can mix, we can have different mixes. We can react to the market. If the mix is going down, we can switch to petrol. If it is going up, we can switch to diesel.”

“So we do have the flexibility in the future in our production system … with what is coming up with our new diesel engine inline and also inline six-cylinder diesel engines and that is a big, big benefit.”