This study focuses on the lubricating effect of microemulsion biofuel in bio-hydrogenated diesel (BHD). The objective was to evaluate the lubricating properties and wear resistance of BHD mixed with microemulsion biofuels using a high-frequency reciprocating Rig (HFRR) following ISO 12156-1: 2018 standards. The microemulsion biofuel consists of rice bran oil, ethanol, Span 80 (surfactant), and n-octanol (co-surfactant) at a certain mixing ratio, blended with two different oxygenated additives. Mixtures of BHD with 1%, 5%, and 10% microemulsion concentrations were tested, yielding six different samples of the blended biofuels. Results showed that neat BHD, lacking oxygenated compounds, exhibited low lubricating properties with a high coefficient of friction and minimal film formation. However, the addition of microemulsion biofuel significantly improved lubricity. The 5% microemulsion concentration demonstrated the best performance, reducing the wear scar diameter (WSD) to 139 μm, the lowest among the tested samples. Further analysis using a 3D microscope and scanning electron microscopy (SEM) on the specimen confirmed the formation of stable, durable lubricating films. These films, enhanced by the presence of unsaturated fatty acids from rice bran oil and the sorbitan ester structure of Span 80, effectively reduced surface friction and wear. The study concludes that microemulsion biofuels can significantly enhance the lubrication properties of BHD, making it a more viable alternative to traditional diesel fuels.