Patent ID: 7454278

Claim:
A method for controlling a powertrain including an internal combustion engine, comprising: providing first power loss terms corresponding to engine operating points that attribute power losses to engine operation at the engine operating points relative to an engine operating point that is maximally efficient with respect to engine power per unit fuel consumption; providing second power loss terms corresponding to engine operating points that attribute power losses to engine operation at the engine operating points relative to an engine operating point that is maximally efficient with respect to engine power per unit emission production; combining the first and second power loss terms at respective engine operating points into a total engine power loss term; providing additional power loss terms corresponding to powertrain subsystem power losses at respective engine operating points; aggregating the total engine power loss term and the additional power loss terms into a total powertrain loss term at respective engine operating points; determining as the substantially minimum powertrain power loss the minimum aggregated total engine power loss term and additional power loss terms at respective engine operating points; and controlling the engine toward engine operating points based on said substantially minimum powertrain power loss.