DIESEL-powered cars appeal to European drivers for their fuel efficiency and power. Carmakers like them because they emit less carbon dioxide than similar petrol engines do, making it easier to comply with stiff regulations. Starting in the 1990s European governments sought to increase diesel’s market share by providing generous tax incentives. By 2011, fully 55% of cars in Europe ran on diesel.

In recent years, however, governments have shifted gear. The advent of electric cars has knocked diesel off its perch as the fuel with the smallest carbon footprint. Diesel also releases greater quantities of nasty gases other than carbon, such as nitrogen oxides, than petrol does. Public awareness of these unwelcome side effects grew quickly after Volkswagen was caught in 2016 disguising the amount of pollution spewed by its diesel-powered cars. In 2012 European governments started to trim back the fuel’s tax advantages. Consumers have fled in response: from 2015 to 2017, diesel’s market share on the continent fell from 51% to 44%.

Diesel’s decline seems far more likely to accelerate than to abate. Britain has announced plans for a total ban on diesel car sales from 2040, as well as a one-off tax increase on new diesel cars. France and Germany have made similar promises. Many cities in Europe, and farther afield, want to eliminate diesel cars from their roads as early as 2025. Governments hope that the void left by diesel will be filled by zero-emission battery-powered models. But mass adoption of such vehicles, which for now are expensive and have limited ranges, still appears a way off. In the meantime, with some countries experiencing up to 20-percentage-point drops in diesel registrations in two years, plain old petrol has made a modest comeback.