Basestock properties are crucial for hydraulic fluids, because the additive amounts are low. The formulated fluids must endure long service life under high humidity levels, elevated temperatures, exposure to various metals and intensive friction in vane pumps. Ester-based fluids have enjoyed success in higher technology hydraulic systems due to reduced operating temperature. Their basestocks are synthesized from petrochemically isomerized C9–C13 monocarboxylic acids, which are esterified to polyols, such as trimethylol propane. In this study, Medium Chain Fatty Acids (MCFA) of C10–C14 have been esterified with TMP and tested under thin film simulation study. Their stability, fluidity, volatility and other properties were comparable to those of mineral and synthetic basestocks. Environmental benefits of MCFA were clearly evident, because they can be produced not only from palm oil, but also from industrial crops crambe and camelina.