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Engine retrofit for clean air - € 1.5 Million


Current engines, while certified on test stands according to the Euro standards in force, exhibit higher noxious emissions while driving on the road. The prize aims at spurring the development of new technologies that can be applied to existing diesel engines and powertrains to reduce emissions of pollutants in real driving conditions to the lowest level possible, in order to improve air quality issues in European cities.


Need for the prize

European citizens in many urban areas suffer from serious health impacts due to air quality issues. This prize aims at reducing the pollution produced by the existing fleet by promoting the development of retrofittable technology (i.e. devices or modification of existing engines). The implementation of the technology should extend the life of retrofitted vehicles while greatly reducing their impact on the urban environment and could allow city authorities to consider measures to encourage their use to solve air quality issues.

Supporting information:

  • According to the European Environment Agency air pollution is the top environmental risk factor of premature death in Europe
  • Tests affirm that on-road NOX emissions of light-duty diesel vehicles differ substantially between laboratory testing and actual on-road driving, with average discrepancies of 4-7 times even for very recent vehicles
  • WHO studies reveal that exposure to air pollutants during pregnancy has been associated with adverse birth outcomes, including reduced foetal growth, pre-term birth and spontaneous abortions
  • Recent studies on air pollution suggest that exposure in early life can significantly affect childhood development and trigger diseases like allergies, asthma or diabetes later in life



The Horizon Prize for the cleanest engine retrofit will be awarded to the contestants who will demonstrate on a running vehicle a solution for an existing engine and powertrains that best addresses the issue of greatly reducing emissions of NOx, particles, hydrocarbons in real driving conditions, while ensuring low levels of undesired other pollutants also in the future. The technology should not affect the operational capabilities of the retrofitted vehicles, for instance it should not significantly increase the fuel consumption, at the same time providing sufficient dynamic performance for normal vehicle driving.



The contest was launched on 20 April 2016 with a deadline on 27 September 2017. Potential participants are encouraged to register for the contest by 12 June 2017. The Prize will be awarded in early 2018.

The rules of contest are available online.



Engine retrofit for clean air

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