Dual-Fuel Engines

Project output

Testing of dual fuel tractor units before and after conversion to dual fuel to analyse engine emissions.


Dual fuel CO2 emissions are 4%, 9% and 12% lower than diesel over urban, rural and motorway phases of the drive cycle.

Total GHG (CO2e) emissions for dual fue are 17%, 13% and 24% higher than diesel over the urban, rural and motorway phases of the drive cycle respectively, as a result of methane slip.

Exhaust after-treatment using an effective methane oxidation catalyst can lead to approximately 5-8% reduction in total GHG.

% fuel saving

Dual fuel operation has the benefit of reduced fuel costs because of the lower cost of natural gas than diesel.

% CO2e Saving

Total GHG emissions for Euro V retrofitted dual-fuel systems are significantly higher than diesel over urban, rural and motorway drive cycles due to methane leakage or ‘slip’.

Cost of implementation

Approx. £18,000

Implementation strategy

Do not implement at this time.


  1. Stettler, M. E. J., et al. (2014). Greenhouse gas emissions from dual fuel HGVs.  Centre for Sustainable Road Freight Technical Report CUED/C-SRF/TR04 ISSN: 2054-4081(Confidential) Department of Engineering, University of Cambridge, Cambridge.
  2. Stettler, M. E. J., et al. (2016),  ‘Greenhouse Gas and Noxious Emissions from Dual Fuel Diesel and Natural Gas Heavy Goods Vehicles.’ Environmental Science & Technology 50,(4): 2018-2026. DOI: https://dx.doi.org/10.1021/acs.est.5b04240