Patent ID: 7100362

Claim:
A method for operating a vehicle to reduce exhaust emissions, the vehicle including an engine, an electric machine, an energy storage device capable of providing energy to operate the electric machine, and a catalyst for facilitating a reaction in exhaust gas from the engine, the method comprising: setting at least one engine parameter to effect an increase in a rate of temperature increase of the catalyst when the engine is operating, thereby decreasing the time required for the catalyst to reach a temperature whereat emissions are reduced; operating the engine such that engine output power is generally constant when an output power of the energy storage device is within a first predetermined range; and adjusting the at least one engine parameter, thereby changing the engine output power, when the output power of the energy storage device is outside the first predetermined range, the at least one engine parameter being adjusted to facilitate a change in the output power of the energy storage device from outside the first predetermined range into the first predetermined range.