Method and system for operating a motor vehicle

A system for operating a motor vehicle, said system comprising:

• an electric machine;
• a combustion engine arranged downstream of the electric machine;
• a common coolant circuit for cooling both the combustion engine and the electric machine, said common coolant circuit being configured to first convey coolant to the electric machine before being conveyed from the electric machine to the combustion engine;
• and
• a cooling device disposed in the coolant circuit to adjust a temperature of the coolant in the coolant circuit in such a way that the cooling device adjusts the coolant to a first temperature, when the motor vehicle is powered solely by the combustion engine, and to a second temperature which is less than the first temperature, when the motor vehicle is powered by the electric machine and the combustion engine.