Late last month, we learned BMW, Daimler, and Volkswagen paid a combined total of $110.84 million in fines for unlawful actions in relation to steel purchases. In short, the three automakers engaged in a cartel scheme with steelmakers and other companies involved in the supply chain. This all began in 2004 and came to an end in 2016. Germany's cartel authority soon began an investigation. And now, all three automakers are subject to yet another cartel-related investigation, this time by the EU Competition Commissioner.

According to the German language Automobilwoche.de, EU Competition Commissioner Margrethe Vestager is confident she can prove all three engaged in illegal agreements in relation to exhaust gas cleaning technologies.

The carmakers are suspected of illegally agreeing on the introduction of SCR catalysts for diesel engines and fine dust particle filters for gasoline engines. More specifically, EU authorities are investigating whether the automakers reached secret agreements on the size of AdBlue tanks, which hold diesel exhaust fluid. Basically, when the car's engine is running, tiny amounts of AdBlue are squirted on the exhaust gas produced, which turns nitrous oxide into nitrogen and water. The diesel variants of the Volkswagen Golf, BMW X5, and Mercedes-Benz E-Class, among others, all used AdBlue fluid.

"We suspect a foul game when it came to using the best technology for emission control or not," Vestager recently told reporters. However, she did not want to speculate any further until a full investigation has been completed. "You have to be sure that this is a legal case and that things weren't done for the best motive," she added. "If we are sure that we have such a case, it will be a strong case."

For example, if the automakers worked together on security issues for the benefit of consumers, the EU Commission would not be getting involved. However, it will do so if it suspects they cooperated in a way that wouldn't benefit consumers. If the three automakers are found to have engaged in cartel practices (again), they will face billions of euros in fines.