Previous aerodynamic heating tests were conducted in the AEDC/VKF Supersonic Wind Tunnel (A) to aid in defining the design thermal environment for the Space Shuttle external tank. The quality of these data has been under discussion because of the effects of low tunnel enthalpy and slow model-injection rates. Recently the AEDC/VKF Hypersonic Wind Tunnel (C) was modified to provide a Mach 4 capability that has significantly higher tunnel enthalpy with more rapid model-injection rates. Tests were conducted in Tunnel C at Mach 4 to obtain data on the external tank for comparison with Tunnel A results. Data were obtained on a 0.0175-scale model of the Space Shuttle Integrated Vehicle at Re/ft = 4 million with the tunnel stagnation temperature varying from 740 to 1440 R. Model attitude varied from an angle of attack of -5 to 5 deg and an angle of sideslip of -3 to 3 deg. One set of data was obtained in Tunnel C at Re/Ft = 69 million for comparison with flight data. This report presents data comparisons betwen the two tunnels for numerous regions on the external tank. Tunnel-to-flight data comparisons are presented for a small number of locations on the nose of the external tank. Keywords: Heat transfer; Mach number; Reynolds number; Aerodynamic heating; Wind tunnel tests; Aerothermodynamics; Enthalpy.