The impact of fuel consumption on merchant ships is categorized in both economic and environmental ways in terms of sustainable blue growth. Apart from the economic benefits of reducing fuel consumption, attention should be paid to related environmental concerns with ship fuels. As a result of global regulations and agreements concerning mitigating greenhouse gases on board, such as the International Maritime Organization and Paris Agreement, ships have to take a step to reduce fuel consumption to adopt these regulations. The present study aims to determine optimal speed diversity depending on ships' cargo amounts and wind-sea states to reduce fuel consumption. Within this context, one-year voyage data from two model sister Ro–Ro cargo ships were used, including daily ship speed, daily fuel consumption, ballast water consumption, total ship cargo consumption, sea state, and wind state. The genetic algorithm method was used to determine the optimal diversity rate. In conclusion, after speed optimization, optimum speed result values are calculated between 16.59 and 17.29 knots; thus, approximately 18% of exhaust gas emissions were also reduced.

燃料消耗对商船的影响可根据可持续蓝色增长的经济和环境两方面进行分类。除了减少燃料消耗的经济效益外，还应注意与船舶燃料相关的环境问题。由于有关减少船上温室气体排放的全球法规和协议（例如国际海事组织和巴黎协定），船舶必须采取措施减少燃油消耗才能采用这些法规。本研究旨在根据船舶的货物量和风海状况确定最佳速度多样性，以减少燃料消耗。在此背景下，使用了两艘姊妹滚装货船的一年航行数据，包括每日船速、每日燃油消耗、压载水消耗、船舶总货物消耗、海况和风况。采用遗传算法方法确定最优多样性率。综上，经过速度优化后，计算出最佳速度结果值在16.59~17.29节之间；因此，废气排放量也减少了约 18%。