Exhaust gas temperature (EGT) is a key indicator in which engine types?

• A. Jet engines
• B. Reciprocating engines
• C. Turbine engines
• D. Both reciprocating and turbine engines

Answer: (D)

Exhaust gas temperature is a useful performance and health indicator for both piston (reciprocating) engines and gas-turbine (turbine) engines. In reciprocating engines, EGT reflects how efficiently combustion is proceeding and how the fuel-air mixture and ignition timing are affecting cylinder temperatures. Rising EGT usually signals a lean mixture, advanced timing, or overheating risks in the cylinders and exhaust system, while very low EGT can indicate a rich mixture or reduced power. Pilots monitor EGT to prevent detonation or overheating and to optimize fuel use at different power settings.

In turbine engines, EGT corresponds to the turbine inlet temperature, a critical limit for turbine blades and overall engine life. As thrust increases, EGT rises, and exceeding acceptable temperatures can cause blade damage or accelerated wear. Engine controls use EGT (often as TIT) to manage fuel flow and keep temperatures within safe bounds, making it a central parameter for both performance and safety.

Because EGT is valuable for both types, the best answer is that it applies to both reciprocating and turbine engines. Jet engines are a subset of turbine engines, so they’re covered by the turbine category, not by themselves alone.