Dealing with global warming and local air quality forces all main sectors to change. This includes the transportation sector. The objective of this course is, starting from the requirements for vehicle propulsion, to present the existing options for vehicle energy converters (powertrains), that have the potential for near-zero pollutant emissions and defossilization, and to practice critical thinking about their likely role. The course deals with powertrains for vehicles. The expectations are that in a sustainable society, transportation powertrains will be a mix between battery electric, fuel cell, combustion engine and hybrids thereof. The combustion engines would then be powered by renewable fuels produced using sustainable sources. The main features of the different energy converters are given, with their pros and cons, after which this is followed up with a more detailed discussion for each of the options. Challenges to the combustion engine fueled by fossil fuels (the current default energy converter) are discussed after which the engine operation on renewable fuels is investigated together with their potential for lowering pollutant emissions and increasing engine efficiency. A short discussion on renewable fuel origins with opportunities and challenges is also scheduled. The different configurations for hybrid powertrains are presented and the criteria for choosing the optimum configurations depending on the application. Plug-in hybrids and range-extended hybrids are discussed. The main features for hydrogen fuel cells and battery electric drive are presented, including advantages and challenges, as well as expected future trends for the different transportation modes (passenger, heavy duty, marine, etc). In addition to lectures, there are exercise classes on energy converter performance parameters and on emissions calculations. Also, there are 2 assignments, one using a game to learn about engine components and the engine operation; and another on critical thinking in sustainable transportation.