A quantum Otto engine with a single ion harmonic oscillator as its working substance is studied for an adiabatic operation at high and low temperature limits. Using the universal optimization method, the heat engine is effectively optimized and found to yield better working conditions in some ranges of temperature ratios. Accordingly, the figure of merit, ψ, is found to be greater than unity in the range: 0<β2β1≤0.12; showing that the heat engine performs better in the optimized condition than in the maximum power working condition. ψ is determined to be less than one in the range 0.12≤β2β1≤0.35 under the same temperature limit ; depicting that the maximum power working condition is preferred to the optimized working condition. On the other hand, in the low temperature limit, the figure of merit, ψ, is found to be greater than unity in the range 3.7<ω1ω2≤18; revealing that optimized working condition is better than the maximum power working condition for the heat engine. In the same temperature limit, ψ is found to be less than one in the range 0≤ω1ω2≤3.7; showing that maximum power working condition is preferred to the optimized one. For the model of heat engine studied, in some ranges of temperature ratio, it is found to work better in the optimized condition, whereas in the other ranges it performs better under the maximum power working condition. So, it is possible to switch the engine between the two conditions depending on one’s need.