Gas Turbine Engine

A gas turbine engine comprising:

• a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the compressor section having a high pressure compressor defining a high pressure compressor exit area (AHPCExit) in square inches, the turbine section having a low pressure turbine;
• a ducted fan having a plurality of fan blades;
• a gearbox having a gear ratio (GR) within a range of 2.0-4.0;
• and
• an overall engine efficiency rating greater than or equal to 1.9 and less than or equal to GR1.5, wherein the overall engine efficiency rating equals
• Q
• ⁡
• (
• D
• 1.56
• T
• )
• 1
• .
• 5
• ⁢
• 3
• ⁢
• N
• 2
• ,
• wherein Q is a gearbox oil flow rate at an inlet of the gearbox measured in gallons per minute at a max takeoff condition, wherein D is a diameter of the fan blades measured in inches, wherein T is a net thrust of the turbomachine engine measured in pounds force at the max takeoff condition, and wherein N is a number of rotating blade stages of the low pressure turbine,
• wherein the gas turbine engine defines a redline exhaust gas temperature (EGT) in degrees Celsius, a total sea level static thrust output (FnTotal) in pounds, and a corrected specific thrust, wherein the corrected specific thrust is greater than or equal to 42 and less than or equal to 90, the corrected specific thrust determined as follows:
• FnTotal×EGT/(AHPCExit2×1000).