Diesel fuel prices have reached a record average of nearly £2 a litre, but some diesel cars may still offer lower running costs compared to petrol vehicles. Recent tests indicate that an entry-level 116hp diesel Volkswagen Golf manual hatchback averaged 65.7mpg, making it around 15mpg more efficient than a petrol manual Golf tested in 2025.
Based on driving 6,000 miles annually, with petrol at 174.7p and diesel at 200p a litre, the diesel Golf was calculated to cost about £115 less per year to run than the petrol version. The diesel Golf would only become more expensive to fuel if diesel reached 228p a litre while petrol remained at 174p.
The popularity of diesel cars has declined significantly, with diesel accounting for only 4% of new cars registered in the UK so far in 2026. This is a sharp drop from 2011, when more than half of new cars were diesel. Factors contributing to this decline include changes to car tax rules in 2017, rising manufacturing costs, and environmental concerns.
Land Rover is noted as the only brand registering more diesel cars than any other fuel type, accounting for over 40% of UK diesel car registrations in September 2026. Volkswagen and Audi are among the other brands that sell a significant number of diesel cars in the UK.