Diesel passenger cars have been declining rapidly in the new car market in recent years. Customers prefer electric or hybrid vehicles to them. So what is the future of diesel engines?
Diesel car: from boom to bust in 40 years
Up until the 1980s, diesel engines still mainly served as a drive for utility vehicles in Europe. With the advent of diesel engines in the range of German manufacturers, including Volkswagen and Audi, they slowly began to gain in popularity. In 1990, they accounted for 13.8% of all first-time registrations in Western Europe. In the following years, by a political decision, CO2 emissions became an ecological whipping boy. Diesel engines are more efficient than petrol engines, so theoretically, they are less polluting, at least in terms of carbon dioxide. That led to a rapid increase in the diesel engines’ popularity, and in 2006 for the first time, their share in the “old” EU countries exceeded 50%. The apogee came in 2011 when diesel-powered passenger cars accounted for as much as 55.7% of all new vehicles registered in the 15 richest EU countries. In the following years, that trend reversed, and in 2020 the percentage of diesel vehicles in new car registrations amounted to only 28%, and in the first quarter of 2021, it fell to 23.2%.
Decreasing popularity of diesel engines
Diesel engines in the passenger car segment are a rarity, only happening outside Europe in India. In the other largest passenger car markets – the USA, China and Japan – virtually all cars are equipped with petrol, hybrid or electric engines. However, the popularity of diesel motors has declined in Western Europe in recent years. While their share in the new car market was still 49.5% in 2016, it had already fallen to just 23.2% after the first three months of 2021.
Several factors have contributed to this:
- the declarations on a ban on diesel cars in major European cities, especially in Germany
- the increasing consumer awareness and numerous scientific studies proving the negative impact of diesel exhaust on health (e.g. growing number of asthma cases)
- the growing popularity of hybrid vehicles, in which the combustion engine is usually a petrol unit, as well as of other alternative drives, including electric
Economical Diesel Motor
However, economics is still the primary factor. Meeting the increasingly stringent emissions standards is becoming more and more costly for car companies. In the so price-sensitive urban and compact segments, where annual mileages are usually relatively low, customers cannot accept higher car purchase costs. That is because it will never pay off through lower fuel bills where annual mileages reach up to 10,000 km. And the circle is complete.
There is no shortage of opinions that diesel engines’ days in passenger cars are numbered, but this is rather a distant prospect. Apart from the city and compact vehicles where diesel motors will probably be soon replaced by hybrid models (combustion-electric, with the former being petrol-propelled), that is not likely to happen in other segments. In the middle class and even SUVs, where high mileage is not unusual, there will be no alternative to the diesel engine for a long time to come in terms of dynamics and running costs.
Soot filters are more frequently fitted in modern petrol engines. The widespread use of direct injection, reduced engine capacity or downsizing, turbocharging, and increasingly stringent emission standards force the fitting of soot filters (GPF – equivalent of the DF from diesel engine) in new vehicles. For the time being, it is not a significant issue. Still, in a few years, the problem-free models on the second-hand market may include mainly hybrid cars and those with unworn petrol engines, preferably without the turbo, direct injection and GPF.