This paper sheds light on some important but underestimated elements of green industrial dynamics: the evolution of firms' eco-innovation strategies and activities within a sector. While eco-innovation sectoral case studies have taken place before, our analysis is distinct in investigating the rate, direction and extent of eco-innovation in the automotive sector, represented here by the main automakers, in order to identify possibly sectoral-specific patterns in firms' strategies, as opposed to divergent strategic behaviors, grounded on evolutionary economic theory. We conduct a two-step empirical analysis using patent data from 1965 to 2012. Our findings suggest a process of co-evolution of firms' strategies and indicate that strong sectoral-specific patterns of eco-innovation are present in this sector from the mid-2000s onwards. For fuel cells technologies, however, we observe the formation of two antagonist patterns. A further econometric analysis is conducted and indicates that the positioning of the firms between these two groups is correlated with the firms' profit margins and the size of firms' patent portfolios.