Society is putting more emphasis on the mobile transportation sector to achieve future goals of sustainability and a cleaner environment. To achieve these goals, does society need to jump to a new combination of fuel and vehicle technology or can we just continue to improve on the current fuels and drive train technology that has powered us the past 70 or more years? Do we need to move to more exotic energy conversion technology (fuel cell vehicles?), or can improving fuel properties further allow us to continue using combustion engines to power our vehicles? What fuel properties can still be improved in gasoline and diesel? Besides removing sulfur, should there be less aromatics in fuels? Should aromatics be eliminated? Is there a role for oxygenates in gasoline and diesel? Do blending oxygenates in fuels help or hinder in achieving the environmental goals? Can we and should we reduce our dependency on crude oil for transportation energy? Why have not the previous government-sponsored Alternative Fuel programs displaced crude oil? The marketplace will determine which fuel and vehicle technology combination will eventually be used in the future. Does the information we know today give us insight to this future? This paper will attempt to address some of the key issues and questions on the role fuels may play in that marketplace decision.