What type of engine cooling system utilizes a radiator?

A liquid cooling system is the correct choice because it actively uses a liquid, typically a mixture of water and antifreeze, to transfer heat away from the engine. The liquid absorbs heat from the engine, then moves through a series of hoses to the radiator. In the radiator, air flows through the fins, dissipating the heat from the coolant before it returns to the engine, thus maintaining optimal operating temperatures.

This system is effective in preventing overheating and allows for better temperature regulation compared to other cooling methods. For instance, air cooling systems primarily utilize air flow to cool the engine without a radiator, while oil cooling systems use oil for lubrication and some heat dissipation but do not involve a radiator as the primary cooling component. Gas cooling systems are generally not a standard classification in heavy-duty equipment, as they refer to cooling methods involving gases in a more abstract sense, rather than a direct application in engine cooling.