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Green Heavy Duty Engine

In the GREEN project, European HD engine manufacturers join forces with suppliers, academia and leading engineering institutes. The common goal is to promote future advanced engine technologies to achieve lower emissions, lower fuel consumption and improved sustainability for future fuels.

Tags: Road


The development of HD engines is undergoing a rapid step in its evolution. Increased demand for fuel efficiency, emissions and global competition are driving forces. The HD (heavy-duty) engines operate under constraints much more severe than those of passenger cars, such as:

  • higher durability (> 600 000 km) of the engine and of the related after-treatment
  • higher mechanical and thermal stress of the engine (heavier load factor)
  • higher pressure on reliability (up-time), investment and fuel economy.

The above constraints characterise the HD engines for their more general applications: not only trucks and urban vehicles but also the rail traction and the inland waterway vessels of the directive 2002/765.

New technologies will help us in meeting future emission and fuel consumption targets by:

  • a new combustion process enabled by variable components
  • new control strategies
  • considering the engine and the exhaust after-treatment as one system
  • considering sustainable fuels.


The main objective of GREEN is to perform research, which will lead to sub-systems for a heavy-duty engine. The objectives should be achieved with strict boundary conditions for: i) a competitive cost base, and ii) the highest fuel conversion efficiency of the diesel cycle, to achieve near-zero real-world, including off-cycle, pollutant emissions and significant reductions of CO2 and other greenhouse gases.

The project puts emphasis on diesel engines for trucks and rail applications, and on natural gas engines for city transport applications. The combination of innovation and durability is strongly supported.

The research targets have been chosen to look beyond all legislation known today. Targeting possible sharpening after the year 2010 with a focus on near-zero real-world emissions (NOx 0.5 g/kWh, PM 0.002 g/kWh, ETC Cycle BSFC = 204 g/kWh for diesel and corresponding targets for natural gas) are set.

Description of work

The work in GREEN is divided into sub-project and crossover activities:

HD gas engine for urban areas: with the objective to reach low gaseous emissions and diesel-engine equivalent fuel consumption by variable valve management, cooled EGR for gas engines and close-to-valve multipoint port-gas injection, and comparing this with DI injection.

Enhanced flexible engine: with the objective to find the best combination and concept to reach emission limits beyond Euro 5, flexible engine components/sub-systems and exhaust after-treatment systems.

Innovative control and air utilisation: with the specific objective to develop the sub-systems for a new combustion process with complete air utilisation and to develop the models for a model-based closed-loop emission control, to regard engine and after-treatment as one system in the future.

High BMEP engine: with the specific objective to investigate the advantages and possibilities of a very high brake-mean effective pressure to reduce fuel consumption as much as possible.

The crossover activities link the subprojects further:

Future HD technology adaptation to rail diesel engines and to develop the rail diesel engine in 2012+

Basic investigations and comparison on fuels: diesel – biofuels – GTL

Further development of a comparable injection system for gas engines – electromagnetic operated control valve (EOCV) system.


The project will provide research results and new components that will enable future emission standards and put European HD manufacturers in a more competitive position.

The introduction of valve management and electronic controls for gas engines will make the NG engine competitive for both emissions and greenhouse gases.

The global conflict of fuel consumption and emissions will be targeted for HD diesel engines. New technologies for improving the fuel efficiency without sacrificing fuel economy look promising. Improved high-tech engine components, such as fuel injection systems, turbine-compressors, variable compression ratio, and many others, are now being electronically controlled and equipped for future engines. GREEN also secures compatibility with future sustainable diesel fuels.

The project targets improvement for both urban and long haulage applications. The rapid start and positive early results look promising for the future. The HD sector has previously been supported on a level that is far too low in relation to the impact on the economy and the environment. GREEN proves that a change will be efficiently governed.