A light viscosity engine oil formulation has been developed based on an extension of the synthesized hydrocarbon fluid (SHF) lubricant technology presented in a recent SAE paper by B. J. Miller, et. al. Utilization of these base materials has enabled the formulation of a product, designated XRN 1669, which provides a significant improvement in both fuel economy and oil consumption control. A combined improvement in these two performance areas has not been attainable in the past with conventional mineral oils. In addition to fuel and oil economy, other critical areas of performance are investigated, including engine cleanliness, wear protection and cold starting capability, as well as ONRI and exhaust emission effects.The superior performance of XRN 1669 compared to premium quality multiviscosity mineral oil products is documented in extensive laboratory, engine and field tests.