Originally, five candidates of nano-material were chosen for making stable nano-dispersions. Nano-graphite particles remain a practical choice for nano-fluids thermal application after taking divergent performance attributes into full account: significant thermal conductivity increases, minimal viscosity increase, low density for better dispersion stability, and relatively low cost, among others. Three different types of commercial antifreeze coolants were chosen for the integration with graphite nano-fluids. Without corrosion inhibitors, our nano-coolants typically fail both ASTM D15 engine coolant corrosion tests. Yet, heating up and adding in electrolytes are two common ways to destroy a nano-particle dispersion. After making adjustments in particle loading, choosing an effective dispersant, and establishing proper dispersant levels, one nano-graphite coolant made from commercial nano-source passed both engine coolant corrosion tests plus the CID AA-52624 A compatibility and storage stability tests. Compared with the base fluid, the nano-graphite coolant’s thermal conductivity has more than a 25 % increase at 2 vol. % particle loading, which is a significant enhancement.