Diesel fuel prices have recently climbed above those of gasoline, marking a shift that is affecting the popularity of diesel-powered vehicles. In both the new and used car markets, diesel cars are seeing a decline. Although diesel has had its supporters, its sales have been on a downward trend for several years, with a significant drop beginning around a decade ago. In 2012, diesel accounted for nearly 73% of new car sales in France, but that number has since dropped dramatically. One major factor in diesel's decline was the Dieselgate scandal in 2015, when it was revealed that some manufacturers had manipulated emissions tests, leading to a loss of consumer trust. Stricter environmental regulations and the introduction of low-emission zones in cities have also reduced the appeal of diesel vehicles. As a result, manufacturers have been moving away from producing diesel engines. By the first half of 2026, diesel accounted for just 2.6% of new car registrations in France. Despite the decline in new sales, diesel still dominates the existing car fleet, with nearly 45% of the 40 million vehicles on French roads running on diesel. However, the recent rise in diesel prices—now over 2.30 euros per liter—has caused many drivers to reconsider their choice. The cost advantage that diesel once had over gasoline has disappeared, and this trend is expected to continue. In the used car market, diesel sales have dropped by more than 12% in June, a decline that has been ongoing for four to five years. At platforms like Aramisauto, the share of diesel cars sold has fallen from 25% to under 10%. Caroom, another used car platform, reports that interest is shifting toward alternative engine types, such as gasoline or electric vehicles. Despite these trends, some drivers still prefer diesel, especially those who travel long distances or regularly tow trailers. Franck Follet of the Sofipel group notes that diesel can still be more economical for high-mileage drivers. Additionally, some budget-conscious buyers are opting for older used diesel cars, as the cost of new vehicles has risen sharply over the past 15 years, outpacing the growth of consumer purchasing power. While the used diesel car market is not entirely disappearing, it is gradually shrinking. With fewer new diesel cars being sold, the supply of used diesel vehicles is expected to decrease over time. The market is likely to shift from being a mainstream option to a niche market, catering to a smaller group of consumers with specific needs.