Biofuels are made from living matter. Biofuels are being developed in response to depleting fossil fuels. Biodiesel is a fuel derived from rapeseed/cooking oil and can be used in diesel-fuelled cars without need for engine modification, which is a major advantage.
Bioethanol would require engine modifications if used as a fuel on its own as it is very corrosive, however, using a small proportion of bioethanol alongside petrol would avoid this problem. Biofuels are not usually carbon neutral as some claim, due to the fossil fuels used in their production.
Compiled by Lucy Bird.