The European Union (EU) Renewable Energy Directive stipulates that only biofuel systems that achieve greenhouse gas emission savings of 60% will be eligible to be considered for the 2020 target of 10% renewable energy in transport. Rape seed biodiesel is a very popular indigenous European biofuel; however, this 60% target is very challenging for the biofuel produced. Tropical biofuels such as palm oil biodiesel tend to be sustainable, due to use of residues and byproduct to satisfy parasitic energy demands. This paper explores, through life cycle assessment methodologies, the whole rape seed system and the potential to improve sustainability. Allocation by energy content attributes almost half the greenhouse gas emissions to rape cake (a coproduct). Indeed rape cake as animal feed displaces imported soybean from Latin America and potential destruction to rain forests. Together with use of glycerol as a source of heat, greenhouse gas savings of 75% maybe attained, indicating a sustainable system. Furthermore use of rape straw pellets in lieu of the environmentally unsound practice of using peat produced from Irish Bogs as a source of domestic heating can lead to a 135% savings on diesel. Interestingly, rape cake as a source of biomethane greatly improves the energy balance of the system but is of little benefit to emissions.