The paper aims to analyze the evolution of eco-innovative activity and strategies in the automotive sector over time. We have chosen to use a patent count methodology tracking the development of selected technologies considered as promising “green technologies” in the automotive sector. Our methodology is based on a normalized Relative Technologic Specialization Index derived from Relative Specialization index, in order to measure the evolution of individual firms’ specialization on the specified technological areas. Our findings show that all the major firms in the automotive industry are diversifying their patent portfolios in response to institutional and demand pressures, as well as new technologic opportunities, in order to generate competitive advantages derived from the introduction of alternative, greener technologies, emerging and becoming more pronounced after the financial crisis in 2008. The analysis demonstrates the current fluid emerging stage of the greening of the economy but also illustrates that eco-innovation is already an important competitive factor.