Methods of projecting (a) tractor hydraulic power and (b) cooling capacity available from the tractor for hydraulic motor usage have been desired to define the tractor hydraulic limits. A theory was developed to define a tractor hydraulic cooling capacity limit based on a pressure compensated (closed center) hydraulic system. The conservation of energy equation was modified for application to a tractor and implement control volume. The theoretical tractor hydraulic cooling capacity limit was compared to wind tunnel cooling test results. A graphical format was developed to present the maximum pressure, maximum power, and cooling capacity on the same plot.