There is a growing requirement for engines operating on a wider range of fuels than when fuel supplies were more stable. The diesel engine, with its high compression ratio and absence of part-load throttling, offers high efficiency. Some widely available alternative fuels, in particular alcohol from biomass, present problems because of their low cetane numbers. The authors report the development of a diesel engine using a combustion system incorporating a high-energy, multi-strike spark to promote smooth combustion. Results obtained with this engine using ethanol are presented to illustrate its ability to handle fuels of very low cetane number.