Ultrasonic assisted grinding (UAG), and minimum quantity cooling lubrication (MQCL) have individually improved grinding characteristics of difficult–to-cut super-alloys in terms of reduced forces and surface roughness. In the present work, a hybrid grinding approach (UAG + MQCL) is utilized, and the effect of fluid's lubricity on grit-workpiece interaction has been investigated during the grinding of Ti–6Al–4V. More lubricious fluid provided less resistance to vibration transfer to the grinding zone, and consequently, the effective amplitude of vibration increased with an increase in lubricity of the fluids. It has governed the mechanism of grinding scallop formation significantly. Additionally, more lubricious vegetable oil yielded the lowest grinding power and higher compressive residual stress. Further, 20–100% improvement in compressive residual stress was noted under UAG. © 2020 Elsevier Ltd