In the postwar years, petroleum products pervaded more and more aspects of Western European life. In this article, we study the origins of this pervasive petroculture through the lens of the Marshall Plan/European Recovery Program (ERP), its Refinery Expansion Program, and the politics of the Organisation of European Economic Co-operation (OEEC). To that end, we examine the creation and expansion of technological infrastructures for petroleum, the institutions that promoted its growing use, and how those changes enabled the transition from coal to oil. The case is made that the ERP and OEEC had a key role in the making of a pervasive petroculture in Western Europe.