Diesel seems to having a bit of a moment right now. And that’s not in a good sense. This wonder-fuel that Indian car buyers loved so much until just two years ago, is now under fire worldwide for being a major pollutant. Diesel is cheaper than petrol and diesel cars can boast mileage figures that are 30-40 % better than petrol-powered vehicles of similar specification. And yet, the earlier marked preference for diesel seems to be declining, with takeup of petrol cars having increased over the last year.
Mass market sentiment started moving against diesel in 2015, with the infamous Volkswagen emissions scandal. Once VW was caught cheating on compliance with emissions norms, government and regulatory authorities have scaled up vigilance levels and some other OEMs have also come under fire for cheating, with software-driven ‘defeat devices’ on diesel engines being the primary culprit in most cases. From here on, there has been a backlash on diesel engines in several quarters, with European cities like Stuttgart proposing to ban older diesel cars from entering the city at times when air pollution levels are excessively high. European authorities are clamping down on diesel cars that do not meet Euro VI norms, and there’s even a plan recommended in the EU, to impose a blanket ban on all diesel cars across major European cities, from the year 2025.
NOx emissions from diesel cars have been blamed for causing respiratory disease and government authorities - including those in India - are in no mood to relent on the subject of allowing the use of older diesel cars, which cause maximum pollution. In fact, with more stringent checks being put in place, OEMs like Porsche and Mercedes-Benz have been forced to recall thousands of diesel-powered cars in recent months. These OEMs still claim that a full ban on diesel cars isn’t the right way to move forward and claim that they have technology that can help them easily and effectively reduce particulate matter and nitrogen oxide emissions from their diesel engines. Why they aren’t already using those technologies on their existing cars isn’t clear yet.
Upcoming BS VI norms will require OEMs to reduce carbon monoxide, hydrocarbons and nitrogen oxides, which will entail the use of expensive cellular ceramic substrates, diesel particulate filters (DPFs) and diesel oxidation catalysts (DOC). Aftertreatment systems can be expensive and complicated, which will also affect OEMs’ margins and perhaps force them to increase prices, which in turn is likely to negatively affect demand for oil burners.
With government authorities beginning to push harder for electrification (and with petrol-electric hybrids being seen as a mid-term solution), things definitely aren’t looking too good for diesel anymore. Sure, diesels won’t disappear tomorrow, but I wouldn’t be surprised if diesel-engined cars go away completely within the next one decade.