Electric vehicles are often seen as a promising way for rationalizing the use of fossil energy in the automotive sector. So far, however, their market success and thus their impact on reducing fossil fuel consumption are rather limited. In this article, the automotive market simulator (AMaSi) is applied to analyze the leverage of manufacturers to support the market diffusion of electric vehicles. This is done by parameterizing the model for the German car market and simulating different product portfolio options regarding the timing of the introduction and the elimination of vehicle models; an aggregated industry as well as an individual manufacturer's perspective is taken into account. The results indicate that manufacturers' portfolio decisions have a strong influence on the market development of electric vehicles and can be used to gain a competitive advantage. Thus, manufacturers should proactively strive to shape the electric vehicle market instead of adopting a waiting position. For policymakers these findings imply that instruments to steer manufacturers' behavior are just as important as those targeted at consumers. The paper broadens the discussion on the levers for the market diffusion of electric vehicles by providing a simulator to analyze manufacturers' portfolio decisions in a competitive setting and by illustrating the necessity to include portfolio decisions when designing mechanisms to foster the market diffusion of electric vehicles.