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There are no quick fixes to long-term energy challenges. To find solutions, governments and industry benefit from sharing resources and accelerating results. For this reason the IEA enables independent groups of experts - the Energy Technology Initiatives, or ETIs1.

Advanced Motor Fuels

Public transport planners must balance investment and maintenance costs with reducing greenhouse gas emissions.*

Balancing costs and emissions

Policy context
Countries worldwide need to improve the fuel economy and reduce greenhouse emissions of road vehicles. Significant improvements in fuel economy can be achieved in the next five to ten years if countries implement the necessary policies. Policy packages composed of fuel economy labelling; standards and fiscal measures have proven to be effective in meeting targets. Renewable energy contributes to CO2 emission reductions. For example, in Europe, 10% of energy in transport must be from renewable sources (e.g. biofuels and renewable electricity). 

The primary focus of the ETI focusing on motor fuels (AMF) is to facilitate the market introduction of advanced motor fuels and related vehicle technologies. The AMF provides a neutral platform for fuel analyses and reporting, drawing on the multifaceted expertise of its participants, industrial partners and networks. There are 16 Contracting Parties, including China and Thailand.

Most public transport systems worldwide include a majority of buses. Transport officials must balance key considerations such as the initial investments required and fleet maintenance costs with the need to reduce greenhouse gas emissions as well as local emissions (mainly particulates, oxides of nitrogen).

One recent AMF project — Fuel and Technology Alternatives for Buses — set out to address how vehicle technology and fuel used affect emissions and fuel consumption. Altogether 11 national laboratories and international agencies participated in the study, sharing existing data and jointly carrying out new measurements in laboratory conditions and on the road.

The study included measurements of fuel consumption, greenhouse gases and regulated emissions in a variety of driving cycles. A large number of fuels were examined, including conventional, synthetic and bio-based diesel fuels as well as alternative fuels for dedicated vehicles.

Lifecycle, or well-to-wheel analysis was carried out for energy consumption and greenhouse gas emissions. The results show that while burning clean fuels such as methane, ethanol and dimethyl ether can provide advantages over diesel in reducing regulated emissions such as particulates or airborne soot, the regulated emissions are first and foremost determined by the sophistication of the engine and the exhaust control system. Greenhouse emissions, on the other hand, are determined by efficiency and the carbon intensity of the fuel.

Lastly, a cost assessment of both direct (purchase, operation and maintenance) and indirect costs (related to the effects on health and the environment) was carried out. The detailed report provides insights for municipal and community transport planning and implementation. 

* Photo courtesy of VTT Technical Research Centre of Finland.

Current projects

  • Alcohol applications
  • Alternative fuels for marine applications
  • Enhanced emission performance and fuel efficiency for heavy duty methane engines
  • Environmental impact of biodiesel vehicles in real traffic conditions
  • Exhaust gas toxicity and particulates from internal combustion engines
  • Particulate measurements of ethanol and butanol in diesel injection engines
  • Performance evaluation of passenger car fuel and power plant options
  • Research on unregulated pollutants emissions of vehicles fuelled with alcohol alternative fuels
  • Synthesis, characterisation and use of hydro-treated oils and fats in engines

For more information:


1.Information or material of the IEA Energy Technology Initiatives, or ETIs (formally organised under the auspices of an Implementing Agreement), including information or material published on this website, does not necessarily represent the views or policies of the IEA Secretariat or of the IEA’s individual Member countries. The IEA does not make any representation or warranty (express or implied) in respect of such information (including as to its completeness, accuracy or non-infringement) and shall not be held liable for any use of, or reliance on, such information.