This article offers a brief description of the aircraft turbine lubrication systems of 1954, along with the lubricant requirements, a review of the general properties of various synthetic lubricants and how certain ones meet these requirements. Comparisons given of different classes of oils are based primarily on their possible use in the aircraft turbine. In a majority of turbojet engines in service in 1954, mineral oils had given good results over the range -65 degrees F to +300 degrees F. For some of the newest models of turbojets synthetic oils were required for the temperature range -65 F to +500 F. Although the gear test rigs show that synthetic oils are equivalent to Grade 1100 mineral oils, much more experience in full scale turboprop engines was required to confirm the point.