Jika reservoir panasnya bersuhu 640 K, efiesiensinya menjadi …
T₁ = 400°K ➝ η = 40%
η = (1 _ T₂ ) 100%
T₁
40% = (1 _ T₂ ) 100%
400
4 ₌ 1 _ T₂ ➝ T₂ ₌ 6
10 400 400 10
T₂ = 240
η₂ = (1 _ T₂ ) 100%
T₁
η = ( 1 _ 240 ) 100%
640
η = 62,5%