A method for operating a vehicle having: an internal combustion engine for driving the vehicle; at least one emission-relevant load; at least one electrical-system battery; and at least one vehicle battery, in which method prior to the start-up of the vehicle, the at least one vehicle battery is charged with electrical energy from the at least one electrical-system battery and, prior to and/or during the start-up of the internal combustion engine, the at least one emission-relevant load is charged with this electrical energy from the vehicle battery.

A powertrain, a control apparatus, and a motor control unit. The powertrain includes a drive motor and a transmission device. The transmission device disconnects a transmission connection between the drive motor and a wheel based on a result of a comparison between a temperature or a viscosity of a lube oil and a preset parameter value, and a rotational speed of the drive motor varies with the result of the comparison between the temperature or the viscosity of the lube oil and the preset parameter value. The drive motor stirs the lube oil through idling, to make the temperature of the lube oil rise rapidly. The powertrain, the control apparatus and the motor control unit provided can improve fluidity of the lube oil at very low temperatures, so that a lube oil pump can be started smoothly.

A powertrain, a control apparatus, and a motor control unit. The powertrain includes a drive motor and a transmission device. The transmission device disconnects a transmission connection between the drive motor and a wheel based on a result of a comparison between a temperature or a viscosity of a lube oil and a preset parameter value, and a rotational speed of the drive motor varies with the result of the comparison between the temperature or the viscosity of the lube oil and the preset parameter value. The drive motor stirs the lube oil through idling, to make the temperature of the lube oil rise rapidly. The powertrain, the control apparatus and the motor control unit provided can improve fluidity of the lube oil at very low temperatures, so that a lube oil pump can be started smoothly.