Which engine cooling mode results in the highest coolant temperature?

The radiator operating mode is characterized by the system allowing coolant to flow through the radiator for effective heat exchange. In this mode, the engine operates at higher temperatures due to the efficient dissipation of heat generated during combustion. The coolant absorbs excess heat from the engine and is then cooled as it passes through the radiator, leading to the highest overall coolant temperature prior to this cooling process.

In contrast, bypass mode refers to a mechanism where the coolant is redirected, or "bypassed," around the radiator, minimizing cooling and resulting in lower coolant temperatures. Mixed mode indicates a combination of bypass and radiator flow, which can lead to intermediate coolant temperatures as some coolant is cooled while other parts remain hotter. Normal mode usually describes standard operating conditions, which typically aim for optimal temperatures rather than the highest. Thus, the radiator operating mode indeed results in the highest coolant temperature due to its role in managing heat removal while maintaining engine efficiency.