* Engine load: Under heavy load, the exhaust gas temperature is much higher, leading to a hotter flow tube.
* Engine speed: Higher RPM generally means higher exhaust gas temperatures.
* Ambient temperature: A hot day will contribute to higher overall temperatures.
* Engine design and cooling system effectiveness: Different engine designs and cooling systems will influence the temperature of the exhaust gases reaching the EGR valve.
* Vehicle's condition: A clogged or malfunctioning EGR system can cause higher temperatures due to increased back pressure.
Therefore, there isn't a single definitive answer to how hot the flow tube gets. It could range from moderately warm to extremely hot, potentially exceeding 500°F (260°C) under heavy load in some situations. However, it's crucial to understand that this is an estimate and could be significantly lower or higher depending on the factors listed above. Direct measurement using an infrared thermometer would be necessary to determine the exact temperature in any given scenario.
