Road transport

Demand for energy related to road transport is expected to continue its decline in the coming decades, but the precise composition of the EU’s energy mix beyond the 2030 to 2050 period is highly uncertain.

Different scenarios have been developed by the International Energy Agency (IEA). According to its estimates, by 2030, oil will still represent around 43% of all energy used by road transportation.

However, if the IEA is correct in its calculations, by 2050, oil used in road transport will represent only 22% of all transport energy. This is because alternative fuels are expected to play a significant role, particularly as compared to other types of transport fuels. An alternative outlook is one featuring a large scale return to gasoline with the challenges of a large scale uptake of electricity and biofuels, as well as hybrid vehicles used in transportation, supports this scenario.


Using realistic assumptions regarding the performance opportunities for gasoline, diesel and hybrid vehicle technologies, we can estimate the relative fuel consumption of the passenger cars of the future. Calculations are based on the assumption that all improvements in engine technology will be aimed at improving fuel efficiency, as opposed to increasing vehicle performance or weight. As the chart below shows, in the coming decades, cars using regular combustion engines will achieve far greater improvements than any other type of technology.

In addition, in the near future the efficiencies of conventional gasoline and diesel engine technologies are expected to converge, particularly as we downsize and turbocharge gasoline engines. More so, policies and regulations setting emission limitations (NOx, SOx, Hydrocarbons, Particulate Matter) are expected to become more stringent for diesel vehicles, resulting in a fuel consumption debit.

Today, the common internal combustion engine (ICE) has an efficiency level of only 25-30%. Even with a state-of-the-art powertrain, there is still a lot of room for improving the energy balance. In fact, only about 25% of all energy produced by a vehicle is actually used for moving it, with the remaining 75% being relatively unused. These missed opportunities include brake energy and heat loss coming from exhaust. In order to create additional options for reducing CO2, these losses must be systematically researched.

In each of these areas of opportunity, recovering and utilising the wasted energy is possible and can result in up to a 10% reduction in CO2. Although research on how to best achieve these benefits continues, their implementation will depend on their cost effectiveness. Please consult the following factsheet for further information on emission reduction and fuel efficiency.