Transport is the second biggest source of greenhouse gas (GHG) emissions in the EU, and contributes about one-quarter of the EU’s total emissions of CO2. Significant reductions in GHG emissions from transport are required if the EU is to achieve its long-term climate goals. This report examines the making and implementation of two of the regulations the EU has put in place to lower emissions from the transport sector: the EU’s revised Fuel Quality Directive (Directive 2009/30/EC) and the cars/CO2 regulation (Regulation (EC) 443/2009). It was found that the relevance of various theories of policymaking in the EU varies with different policy phases. A policy-network understanding of EU policymaking is strengthened when assessing the policy-initiation phase. The Commission played a key role in this phase and drafted legislation in close collaboration with the car and oil refining industries. An intergovernmentalist understanding of EU policy-making is strengthened when assessing the decision-making phase. In this phase, member states defending the interests of their domestic industries had strong influence, but the European Parliament played an important role in this phase too, employing its power in the co-decision procedure. Finally, the implementation process is best understood as a multi-level governance process in which several actors and institutions - notably the Commission, member states, industries, and NGOs - influenced the process.