Which statement best describes the information shown on a cooling system pressure-temperature chart?

• A. It shows fuel quality indices.
• B. Only the engine oil value is shown.
• C. It compares coolant pressure and temperature to specification to assess the cooling system.
• D. Only the air intake temperature is shown.

Answer: (C)

The chart is used to verify the cooling system by showing how coolant pressure relates to temperature and what the system should read at various temperatures. By comparing the actual pressure at a given temperature to the specification on the chart, you can tell whether the cooling system is functioning within design limits. If the readings align with the spec, the system is good; if they don’t, it suggests issues like leaks, a faulty pressure cap, or other cooling system faults. This chart isn’t about fuel quality, engine oil values, or air intake temperature, so those options don’t describe what it shows.