Collectively, the aviation and maritime transport industries contribute to 5% of global greenhouse gas (GHG) emissions. Sustainable fuels are an alternative energy source that provide comparable energy density to traditional petroleum fuels that have a carbon net-zero lifecycle. The fuels thermophysical properties influence the injection and combustion characteristics of the engines they are used in, which ultimately impacts their efficiency. The thermophysical properties of fluids group at NIST has experience studying the thermophysical properties of a wide variety of fluids including refrigerants, lubricants, and fuels. We are currently investigating the thermophysical properties of sustainable fuels to aid in their integration into the fuels market. Our group has state-of-the-art instrumentation to measure properties including the phase behavior, density, speed of sound, and thermal conductivity. We welcome proposals that would yield thermophysical property data primarily intended for model development that investigate how the molecular size, molecular structure, and polarity of fuel constituents impacts their thermophysical properties. Measurements on both pure fluids and mixtures are of interest. Opportunities also exist to expand the range and capabilities of our instruments or propose the development of new measurement techniques. We especially encourage proposals that combine experimental studies with theory and modeling.