How the latest EU emissions scandal is different than Dieselgate

A recent statement by the European Union alleges that BMW, Daimler, and Volkswagen conspired to cheat on emissions in two ways. The companies delayed the implementation of particulate filters on gasoline engines and agreed to limit the size of the AdBlue urea tanks on diesel engines.

While these charges do involve some degree of emissions cheating, it’s different than Volkswagen’s 2015 emissions scandal. That case resulted in approximately $25 billion paid out by VW in the form of payments to owners, fines, and penalties, environmental mitigation, and zero-emissions vehicle infrastructure. Dieselgate, as the scandal is commonly known, centered primarily around a “defeat device” that would allow the cars to run cleaner during emissions testing and up to 35 times more dirty in real-world conditions.

With the new scandal, no specific defeat device is alleged, at least at this point. The implications are just as serious, however, given that the situation involves three companies and five automotive brands (Audi and Porsche are part of the VW group).

How it worked

The first allegation involves the urea-injection tanks used in the selective catalytic reduction (SCR) systems on diesel engines to reduce nitrogen oxide emissions. The fluid used in these systems is known as AdBlue or DEF (Diesel Exhaust Fluid), and the use is widespread in diesel cars and trucks today. The charge by the EU is that the German automakers agreed to limit the size of the DEF tanks in cars. This would allow for easier packaging in vehicles designs, and the agreement would prevent competition in terms of tank size. To ensure that the refill intervals of these tanks would be at longer intervals (thus reducing the annoyance to the buyer), the automakers agreed to limit the use of the fluid. According to an Autocar report from when the investigation began in 2017, the SCR systems would only work in a certain range to prevent excessive consumption. That would result in higher-than-allowed emissions but does not constitute a direct cheat for emissions test like in VW Dieselgate.

Think of a particulate filter like a trap for ashes, only the ashes involved are microscopic in size. This is a common exhaust treatment for diesel engines, although it’s a relatively new requirement by the EU for gasoline engines. A particulate trap collects and stores particulate matter during normal engine operation, and from time to time the engine will adjust the combustion cycle to burn off the particles—kind of like the cleaning cycle of an oven. Mercedes-Benz was first with a gasoline particulate filter on the 2015 S 500. The EU charges that the three companies intentionally delayed the implementation of these systems.

Why they did it

There are several motivations for automakers to try to skirt emissions regulations, but the main ones are cost and fuel efficiency. Exhaust treatment systems add to the price of the car, and not in a way that an automaker can realize a profit. Consumers generally don’t pay for lower emissions, so the cost for these systems has to be baked into the base price.

Second, these systems reduce fuel economy because a combustion cycle that enables SCR or burn-off of particulates is not always the most efficient. Fuel economy is a motivating factor for consumers, and automakers do everything they can to squeeze fraction of a mile per gallon out a car. Hindering a car’s efficiency without adding some trade-off that people might want, such as power or towing capacity, is a tough pill to swallow in light of ever-tightening standards.

What this means for diesel

It’s another blow to the diesel engine, especially in passenger cars. The Volkswagen Group is already running away from the fuel, instead pivoting to electric vehicles. And several European cities are discussing outright bans of diesel vehicles on their streets.

According to the Associated Press, Mercedes-Benz doesn’t expect to face a fine, as it blew the whistle on these plans. Volkswagen also claims to have cooperated early and foresees leniency. This might seem like a good argument for the industry to self-police, but that’s only because these companies got caught. This is also the third major emissions scandal in recent years, after VW’s misdeeds and FCA’s own settlement on Jeep and Ram diesels earlier this year.  

From a practical perspective, the cost of all the exhaust after-treatments required for diesel to meet the stringent future emissions standard makes diesel less and less practical. Automakers will either have to swallow some of the additional cost associated with diesel engines, charge even more to consumers, or stop selling them. With gasoline engines closing the gap to diesel in terms of efficiency and electric vehicle ranges increasing, it seems less and less likely that diesel will continue to be an option in the EU.