Cooling System
The cooling system for engine B4204 differs in several ways compared to the previous engine variants. Instead of a mechanical water pump there is a 400W electric water pump. The thermostat is also electrically heated.
With an electric water pump the water pump can be demand controlled as required. This results in a lower load on the engine, resulting in lower fuel consumption and better power. With electric heated thermostat one can regulate the thermostat opening temperature as needed.