The maritime sector is working hard to reduce greenhouse gas emissions. Overall, the shipping industry is under considerable pressure to identify innovative solutions, including a transition from conventional to cleaner fuels by 2050. The most promising future fuels are ammonia, ethanol and methanol, which have lower viscosities than current fuels. These new generation fuels are sustainable and have the potential to significantly reduce greenhouse gas emissions. Positive displacement meters are one of the most common types of flow meters used to measure fuel in the marine sector. However, they usually require a certain viscosity to perform properly. The aim of this study is to investigate the measurement performance of a prototype positive displacement fuel consumption meter capable of measuring next generation marine fuels and fuel blends with these and established fuels. The paper outlines the development of the prototype and how it was subsequently improved. Measurements were carried out on the prototype with fuels of different viscosities and line pressures relevant to shipping. The results prove that the meter operates almost independently of viscosity and pressure, making it suitable to accurately measure today’s (current fuels), tomorrow’s (blended fuels) and future fuels. Finally, suggestions for further improvements are given.