'The oil of the engine’ describes the role of intergovernmentalrelations within a multitiered system. It is the unseen layer that allows the various parts of government to operate, to reach their potential and to serve the interests of the whole. Cooperative government is meant to strengthen each of these spheres and not to reduce or curtail their effectiveness This KAS Policy Paper by Bertus de Villiers and Jabu Sindane provides a general albeit brief overview of the system of cooperative government in South Africa and an assessment of how the system operates in practice.