Conventional Internal Combustion Engine

For vehicles with conventional internal combustion engines, the distinction is still straightforward: there are liquid and gaseous fuels, and corresponding engines. Currently, most passenger cars are equipped with gasoline or diesel engines that run on liquid fuels. Passenger cars with gas-powered engines that run on, for example, autogas, natural gas (Compressed Natural Gas, CNG), or biomethane play only a minor role. Diesel engines dominate the heavy-duty commercial vehicle sector - gasoline engines are not used here. Natural gas trucks, powered by gaseous (CNG or biomethane) or liquid (Liquefied Natural Gas, LNG, or bio-LNG) fuel, are indispensable as a bridging technology.

Electric car or battery-electric powertrain?

When it comes to electric cars, experts distinguish between battery-electric and fuel-cell-electric propulsion systems. In most cases, however, the term “electric cars” refers exclusively to battery-electric vehicles. So far, two types of battery-electric propulsion systems have established themselves on the market. These are purely battery-powered vehicles (Battery Electric Vehicle, BEV) and plug-in hybrids (Plug-In Hybrid Electric Vehicle, PHEV). In addition, electric vehicles with a range extender (Range Extended Electric Vehicle, REEV) are gaining in importance. Their common feature: The batteries are charged directly from the power grid. In BEVs, the energy for propulsion comes exclusively from the battery. Battery-electric hybrid vehicles are electric vehicles that, in addition to an externally rechargeable battery, have an additional propulsion system. PHEVs combine an internal combustion engine with an electric motor. In REEVs, a small internal combustion engine serves as a mobile power generator. By burning fuel, it generates electricity for the electric drive when needed, thereby extending the vehicle’s range.

Fuel Cell or Hydrogen Propulsion?

In principle, fuel cell vehicles (Fuel Cell Electric Vehicles, FCEVs) are also classified as electric vehicles. However, they do not use a battery as an energy storage device; instead, they are refueled with hydrogen, which is converted directly into electrical energy within the vehicle. FCEVs therefore also have an electric motor. Nevertheless, FCEVs are often referred to as hydrogen vehicles. Vehicles with hydrogen internal combustion engines may also be part of the future powertrain mix. Their use is expected to be predominantly in the commercial vehicle sector. Manufacturers are working on initial small-scale production runs and pilot projects.

Which powertrain will prevail?

In passenger transportation, the technological path is foreseeable to lead to direct electrification. Currently, BEVs and PHEVs are available on the market as mass-produced vehicles in most vehicle segments. When it comes to FCEVs, there is not yet a corresponding variety of models available to customers. As of the beginning of 2026, there were approximately 3.1 million electric vehicles on German roads. The share of electric vehicles among newly registered passenger cars is steadily increasing. In the first half of 2026 alone, their share amounted to nearly 37 percent. You can find an overview of the pros and cons of the three most important powertrain concepts in the passenger car segment - electric, fuel cell, or conventional internal combustion engine - here.

For heavy-duty commercial vehicles, alternative powertrains are available as production vehicles for most segments. Depending on the application and the vehicle’s gross weight, the powertrain concepts here range from battery-electric (fully electric or hybrid) to hydrogen in combination with a fuel cell or a hydrogen-powered internal combustion engine. Light commercial vehicles with battery-electric powertrains for urban distribution are well established. BEVs are also available for use by medium-duty trucks in regional and distribution transport. In cities, BEVs and FCEVs are already in permanent service or pilot operations as part of municipal bus fleets. BEV trucks for heavy-duty distribution and long-haul transport are also available on the market.

Ban internal combustion engines or replace fossil fuels?

Thanks to the legally mandated blending of renewable fuels - which are currently mostly still low in CO₂ - into fossil fuels (petrol, diesel, natural gas: CNG, LNG), even vehicles with conventional internal combustion engines are already making a significant contribution to reducing greenhouse gas emissions from road traffic. Depending on the type of fuel and engine, renewable fuels are blended with fossil fuels or can replace them entirely.

There are many different production pathways for green fuels. Generally, a distinction can be made between biofuels and electricity-based fuels. Biofuels are further subdivided into first-generation biofuels, which are classified as low-CO₂ fuels, and advanced biofuels (CO₂-neutral biofuels), which are often referred to as second- and third-generation biofuels. Advanced biofuels and electricity-based fuels already make it possible today to drive internal combustion engine vehicles in a nearly climate-neutral manner. Since 2024, HVO100 fuel has been permitted for sale at German petrol stations. HVO100 is the first CO2-neutral biodiesel available as a pure fuel. Renewable fuels are an indispensable component, particularly in terms of the contribution that existing fleets of passenger cars and trucks can make to reducing greenhouse gas emissions in transportation.

To achieve national and European climate protection goals in the transportation sector, policymakers must focus on two key levers, particularly in road transport: a rapid transition to new propulsion systems and a shift to new fuels. Electric vehicles will dominate our future propulsion mix for passenger cars and commercial vehicles. Nevertheless, the industry opposes a blanket ban on internal combustion engines. Every type of powertrain has its own specific advantages and disadvantages. It is therefore important to carefully weigh which powertrain concept is best suited for specific applications in passenger and freight transport. The goal is to reduce the use of fossil fuels. For the industry, therefore, a technology-neutral approach is of crucial importance.