Contrary to S-curve diffusion theory, historical introductions of alternative transportation fuels (ATFs) exhibit a variety of adoption patterns. Analysis of ATF introductions in the market place of natural gas in Argentina and New Zealand and ethanol in Brazil reveals that the aggregate dynamics cannot be traced back to a single dominant mechanism of change. ATF diffusion embodies several coevolutionary processes, including: the development of the vehicle installed base, consumer preferences and driver behavior, the evolution of technology and complementarities, such as a fueling infrastructure, and the transformation of fuel and automotive supply chains. Further, their diffusion is conditioned by institutional contexts. A behavioral dynamic model with a broad system boundary helps understanding failures and successes of ATF diffusion. While successful diffusion, such as promised by the Brazil case, is possible, the analysis reveals complex dynamics, requiring long periods of commitment and coordination across various types of actors. The paper develops initial steps towards a framework for studying the rich dynamics of socio-technical systems change. Central in such a process based framework are the mechanisms within interorganizational fields, capturing decisions and actions from consumers, organizations across industries and policymakers, and including the system-physiological aspects. We discuss implications for policy and strategy.