The maritime fuel grade known as Very Low Sulphur Fuel Oil has emerged as a critical component in global shipping operations due to stringent emissions regulations such as the International Maritime Organization (IMO) 2020 threshold that limits sulphur content in fuel oil used by vessels to 0.50 % m/m. VLSFO represents a new generation of blended residual and distillate streams designed to meet the sulphur limit while delivering reliable combustion, compatibility with existing engines, bunkering infrastructure and logistics networks. Typically, VLSFO is produced by blending low-sulphur distillate streams with residual fractions, ensuring that the final sulphur content is at or below 0.50 % while maintaining suitable density, viscosity, stability and combustion behaviour. The shift to VLSFO has necessitated adaptations across the supply chain—from refinery processing, bunkering terminals and storage logistics, to vessel fuel-system management, compatibility testing and operational procedures.

On-board ships, the use of VLSFO requires careful fuel management due to its distinct properties compared with conventional high-sulphur fuels. Because VLSFO blends may contain varying proportions of residual components and distillates, challenges such as stability, compatibilisation, wax precipitation, sediment formation and clogging of filters have been reported and need proactive monitoring. Operators must manage handling parameters (e.g., settling-tank temperature, purity, compatibility with other fuel batches) to ensure operational reliability. The fuel’s performance directly affects the vessel’s compliance with emissions regulations, cost of bunkering, engine performance, maintenance intervals and long-term operational risk. Moreover, VLSFO plays a role in enabling shipping companies to avoid scrubber retrofit costs or switching to more expensive fuel alternatives by offering a direct route to compliance using existing engines and infrastructure. This move has driven adoption of VLSFO as a compliant alternative to traditional high sulphur fuel oils and underpins the transition to marine fuel oil with ultra-low sulphur performance levels.

The long-term outlook for VLSFO is shaped by regulatory drivers, global bunker-fuel supply dynamics, refinery feed-stock shifts, blending capabilities, regional availability and price differentials versus distillate fuels or alternative fuels (e.g., LNG, bio-fuels). As the shipping industry continues to decarbonise and adapt to evolving emissions and fuel-quality standards, VLSFO remains an essential transitional fuel. Its broad uptake across major bunkering hubs reflects its significance in supporting a compliant, practical and scalable fuel supply solution for global maritime operations.