What is diesel?
Diesel, also called gas oil, is a fuel derived from crude oil. Used mainly in diesel-type internal combustion engines, it is at the heart of many discussions about the energy transition, pollution and pump prices. Long considered a cheaper alternative to petrol, its image has been called into question in recent years.
Origin and composition of diesel
Diesel comes from the fractional distillation of crude oil. It is obtained at an intermediate temperature between lighter products such as LPG or petrol, and heavy products such as domestic heating oil. At the refinery exit, diesel is often enriched with additives that improve its properties, notably to resist the cold (winter diesel), improve combustion, or reduce particulate emissions.
The exact composition varies slightly between suppliers, but in France diesel is standardised (EN 590) and may contain up to 7 % biofuel (FAME type, fatty acid methyl esters), which makes it a partly renewable fuel.
Why was diesel favoured for so long in France?
Until the early 2010s, B7 diesel enjoyed favourable taxation compared with petrol. This encouraged many French motorists to buy diesel vehicles, notably for their better range and lower consumption (on average 15 to 20 % less than petrol).
Diesel is particularly appreciated by drivers who often drive on motorways or make long journeys, because its engines generally offer greater longevity.
A now controversial fuel
Since the “Dieselgate” scandal in 2015, the spotlight has turned on the polluting emissions of diesel engines. Although more frugal in CO₂ than petrol, diesels emit more fine particles and NOx (nitrogen oxides), gases harmful to health and responsible for air pollution in large cities.
In response, taxation has changed. Taxes on diesel have gradually been brought closer to those on petrol. Many Low Emission Zones (LEZ) ban access to older diesel vehicles, particularly those classified Crit’Air 4 or 5.
Differences between standard diesel and premium diesel
At service stations, two types of diesel are often found:
- Standard diesel: the most common, compliant with the European standard EN 590.
- Premium diesel (Excellium, V-Power Diesel, etc.): enriched with specific additives to optimise combustion, protect the engine and reduce emissions.
Premium diesel is often sold a few cents more expensive. Its value depends on the vehicle, the driving style and the conditions of use (climate, mileage, etc.).
What is the price of diesel in France?
The price of diesel varies daily depending on oil prices, seasonal demand and taxation. In April 2025, its average price is about 1.75 € per litre, but large disparities exist depending on the region and the type of station (supermarket, motorway, independent station).
👉 Check the diesel fuel page to see current prices by département and municipality.
Environmental impact and alternatives
Although still used by a large part of the vehicle fleet, diesel tends to be gradually replaced in passenger cars:
- Petrol hybrids and electric cars are gaining popularity, especially in urban areas.
- LPG engines, cheaper and cleaner, are also making a comeback.
However, diesel remains hard to replace in freight transport, agriculture and professional uses, where its energy efficiency remains an advantage.
What future for diesel?
By 2035, the European Union plans to end the sale of new combustion-engine cars, which will include diesel engines. Nevertheless, vehicles already on the road will keep using diesel for many more years.
Some manufacturers are investing in alternatives such as synthetic diesel or HVO (Hydrotreated Vegetable Oil), a synthetic diesel made from plant residues.