Which Fuel at the Pump?

Marine fuel choice in ECAs: MGO vs ULSFO

Marine fuel choice in Emission Control Areas (ECAs) is a critical operational decision. Although Marine Gas Oil (MGO) and Ultra Low Sulphur Fuel Oil (ULSFO) both comply with the 0.1% sulphur limit, they behave very differently onboard.

Marine Gas Oil (MGO) is a clean, “clear and bright” distillate fuel. It behaves much like high-grade diesel and usually requires no heating. As a result, MGO is often seen as the most reliable option for ECA operations. However, its low viscosity can increase the risk of fuel leakage and reduced lubricity, which may lead to injector or fuel pump wear.

Ultra Low Sulphur Fuel Oil (ULSFO) is typically a blended fuel containing residual components. It is often cheaper and more lubricious than MGO. However, ULSFO is technically more demanding. It usually requires onboard heating to achieve the correct injection viscosity. In addition, incompatibility between different fuel batches can cause chemical instability and sludging.

In this episode, Captain Barry Sadler discusses a recent act of pilotage where marine fuel choice appeared to coincide with main engine fluctuations. As a result, the Master declared a potential machinery problem. Drawing on his current hands-on pilotage experience, Barry explains how fuel management decisions in ECAs can directly affect engine reliability and operational safety across Northern Europe.