An investigation is reported on the thermal aspects of grinding with single layer electroplated CBN wheels. The topography of these wheels is not periodically restored by dressing or truing, so the grinding behavior progressively changes as the wheel wears down. Straight surface grinding experiments were conducted to determine the effect of wheel wear and fluid flow on the grinding temperatures and energy partition. Low energy partition values of 3%–8% were obtained at temperatures below the fluid burnout limit. The energy partition results were analyzed in terms of a topographical analysis of the wheel surface and a thermal model which accounts for the removal of heat at the grinding zone by conduction to the abrasive grains and to the grinding fluid.