Three facts about diesel
Despite all the debate, diesel still makes an important contribution to the implementation of the European climate protection targets.
Three reasons why this is the case:
1. Low emissions of the greenhouse gas CO2
On average, a diesel engine consumes around 25 percent less fuel than a petrol engine. It therefore causes around 15 percent fewer CO2 emissions per kilometre driven.
As example vehicles, we will use two identical vehicles from a German manufacturer – one with a petrol engine and one with a diesel engine. On a car journey from Berlin to Munich – which is a stretch of motorway of around 600 kilometres – the diesel version emits around 53.4 kg of CO2. A comparable petrol model from the same manufacturer produces about 62.4 kg of CO2 on the same route. For these example vehicles in the compact class, this corresponds to emissions of 104 grams of CO2 per kilometre for petrol engines and 89 g/km for diesel engines.
(Basis: Manufacturer specifications, May 2020 )
2. Low nitrogen oxide and particle emissions
Within the framework of the current Euro 6 legislation, the emission of nitrogen oxides (NOx) and fine dust particles in modern diesel vehicles is once again being significantly reduced. This is made technically possible by comprehensive measures for exhaust gas aftertreatment in vehicles, such as exhaust gas recirculation, the particulate filter or selective catalytic reduction (SCR cat), and AdBlue.
Compliance with the stricter emission values must also be documented during type approval in the new and improved measuring cycle WLTP and in connection with the practical determination of real driving emissions (RDE).
3. Diesels tolerate synthetic fuels
Research is currently being conducted worldwide on the industrialisation of processes for the production of synthetic fuels (e-fuels). The first pilot plants for this are being operated and they produce synthetic fuel in small quantities from water and carbon dioxide using electric current. However, just like a battery-powered car, this fuel is only CO2-neutral if the electricity used is generated sustainably using solar collectors, wind energy or hydropower. E-fuels could be mixed with normal diesel in the future and thus reduce CO2 emissions. They would also not need a separate logistics chain.
Diesel engines and petrol engines have their respective advantages. A small car – which is mainly used over short distances – can generally be used more efficiently and more economically with a petrol engine. On the other hand, larger vehicles with higher mileages can fully exploit the fuel consumption advantages of diesel. There is therefore no way around diesel engines in the short and medium term, particularly in terms of climate protection.