With 25% better fuel economy and lower carbon emissions than their gasoline-powered equivalents, diesel engines once promised a cleaner future for the automobile industry. Lately, however, the reality has become messy.
Reducing levels of soot, dust and other particulate matter released by diesel-powered vehicles had long been the foremost challenge facing the diesel industry. Exposure to these substances was linked to high incidence of respiratory illnesses, such as asthma and bronchitis. Nonetheless, the issue was largely resolved during the 1980’s with the introduction of particulate matter traps, capable of filtering-out 95% of these harmful substances. In recent years, however, diesel has encountered a new challenge: reducing its NOx or, nitrogen oxide, emissions.
Research has found that NOx emissions are more harmful to respiratory health than CO2, and according to The Economist, are the cause of a large number of premature deaths—perhaps 58,000 a year in America alone. Given that diesel engines release NOx at twenty times the rate of gasoline-powered engines, car manufacturers have found themselves compelled to search for a solution.
Diesel-powered trucks and large passenger automobiles have successfully employed “selective catalytic reduction”, or SCR, to cut NOx emissions. SCR works by reducing NOx to harmless nitrogen and water through a chemical process that takes place inside a catalytic converter installed within the vehicle. However, the bulkiness of the converter and the rest of the SCR apparatus has prevented the technology from being used as effectively on lightweight, family-sized diesel cars. This has forced car manufacturers, like Volkswagen, to search for alternatives.
After failing to design a system capable limiting NOx emissions while also maintaining its guaranteed high level of fuel economy, Volkswagen resorted to installing what are called “defeat devices” inside a number of its automobile models. Banned by environmental regulatory agencies worldwide, “defeat devices” allow a vehicle to “sense” when it is undergoing an inspection and distort emissions readings in order to meet the required standard.
Last September, after an investigation conducted by the EPA revealed that Volkswagen was “cheating” on its emissions tests, the company came forward and admitted to installing the devices inside 11 million diesel vehicles worldwide. Since coming forward, the auto-making titan has endured tumbling stock prices and endless lawsuits. More turbulence in sales and additional lawsuits are expected to follow.
General mistrust in diesel as a result of the controversy, now referred to as, “Dieselgate”, is beginning to manifest itself worldwide. In January of this year, French government authorities raided the offices of diesel-car manufacturer, Renault, after discovering that like Volkswagen, a subset of its vehicle models were exceeding limits on emissions. The company has since recalled more than 15,000 of its cars and according to The Financial Times, has experienced a sharp decline in shares as a result of investor fears. Renault is denying that it “cheated” and has attributed the discrepancy in emissions readings to a “calibration error”. Nevertheless, the incident has undoubtedly helped to further tarnish diesel’s image.
Despite the trouble Dieselgate has fomented, there may perhaps be a silver lining after all. In particular, the discovery of the Volkswagen’s wrongdoing, in and of itself, shows that regulatory agencies and governments are beginning to enforce their emissions standards more rigidly. What Volkswagen and Renault have experienced will perhaps serve as a warning to all other automobile manufacturers that noncompliance with these standards will be met with severe consequences.
- Konstantine Tettonis
Photo: The Independent