The current momentum in the electrification of the car fuels hope for a transition in mobility. However, electric vehicles have failed before and it is thus asked: What is the potential of e-mobility developing as a sustainable system innovation? In order to deal with this challenge analytically, a theoretical framework is developed: the concepts of transformative capacity of a new technology (do electric vehicles trigger 'social' innovations, e.g. new business models or use patterns?) and system adaptability (how stable is the mobility regime?) are introduced and the issue of sustainability is discussed. This framework will be explored for the German innovation system for e-mobility. It can be shown that electric cars will only be successful when part of a system innovation and that the German innovation system is dominated by regime actors and thus potentially used as a way to fend off more substantial change.