What does EGT measure and why is it important?

• A. Exhaust Gas Temperature; indicates turbine inlet temperature and fuel/air ratio health; high EGT can indicate over-fueling or lean conditions.
• B. Engine Gas Temperature; measures ambient temperature.
• C. Exhaust Gas Timing; used for maintenance scheduling.
• D. Emissions Gas Temperature; monitors NOx.

Answer: (A)

Exhaust Gas Temperature is the temperature of the gases as they leave the combustion chamber and head toward the turbine. This reading ties directly to the combustion process inside the engine: it reflects how hot the turbine inlet condition is and, to a practical extent, how the fuel and air are being balanced. Keeping EGT within design limits is crucial because an elevated EGT means the combustor is running hotter than intended, which can stress turbine blades and shorten life.

A rising EGT usually signals that the fuel-air mix isn’t producing the right burn—often associated with over-fueling or a condition that effectively creates too much heat in the combustor. Conversely, persistently low or abnormal readings can point to fuel-control or air-delivery issues, and they provide a quick diagnostic check beyond what ambient temperature readings or timing discussions would offer.

Other terms don’t describe what EGT measures or why it’s watched: it’s not about ambient temperature, timing, or general emissions temperature; it’s specifically the exhaust temperature that serves as a direct indicator of combustion heat entering the turbine.