An optimized rotorcraft propulsion system incorporating a foil air bearing supported Oil-Free engine coupled to a high power density gearbox using high viscosity gear oil is explored. Foil air bearings have adequate load capacity and temperature capability for the high-speed gas generator shaft of a rotorcraft engine. Managing the axial loads of the power turbine shaft (low speed spool) will likely require thrust load support from the gearbox through a suitable coupling or other design. Employing specially formulated, high viscosity gear oil for the transmission can yield significant improvements (~ 2X) in allowable gear loading. Though a completely new propulsion system design is needed to implement such a system, improved performance is possible. Based upon this overview, it is apparent that an Oil-Free turboshaft engine can be designed to mate with an advanced gearbox that provides both shaft speed reduction and low spool axial load support for the engine. Such an 'Optimized Propulsion System' offers tangible benefits for rotorcraft, yet research challenges and questions remain. Long term and intermediate goal research must be conducted on a variety of fronts before such a system is demonstrated. Hot core bearing development and tests, integral starter-generators, advanced axial load carrying couplings and possibly new centerlines are among the topics that will need to be addressed. Nonetheless, the potential weight savings offered by such an approach merits consideration. Further, deployment of oil-free bearing technology into rotorcraft will help mature the technology for larger more advanced systems such as turbofans and potentially space power generation systems as well.