Method for operating a drive device for a motor vehicle and corresponding drive device

A drive device for a motor vehicle, comprising:

• an internal combustion engine and an electric motor, and a drive shaft of the internal combustion engine can be coupled to a motor shaft of the electric motor by a shift clutch, wherein the shift clutch can be adjusted to a desired clutch torque over a dragging period for startup of the internal combustion engine, wherein the drive device is designed such that, prior to the startup, a quantity of heat that is expected to accrue in the starting clutch during the startup is predicted and, when the predicted quantity of heat exceeds a limit value, at least one operating parameter of the drive device that influences the startup is chosen to reduce the quantity of heat expected to accrue,
• wherein the quantity of heat is determined from at least one of the following values:
• a duration of the dragging period, the desired clutch torque, a difference in speed between a speed of the drive shaft and a speed of the motor shaft, a fuel pressure, a predicted speed gradient of the speed of the drive shaft during the startup, and a startup mode of the internal combustion engine.