1. The problem statement, all variables and given/known data The highest theoretical efficiency of an engine is e=(TH-TC)/TH where TH is the highest and TC is the lowest temperature during the circuit process. In a test car with a stirling engine the highest temperature during the circuit process is 700 °C and the lowest temperature is 100 °C. Calculate the highest possible efficiency. 2. Relevant equations e=(TH-TC)/TH 3. The attempt at a solution 1 – 100/700 = 85,7% But apparently the answer should be 61,7%. What other factors needs to be included here?