August 19, 2025
According to LR’s latest FOBAS Fuel Insight report, global bunker fuel quality remained resilient in the first half of 2025 despite growing fuel diversity.
The findings highlight how improved testing, data sharing and operational practices are supporting shipowners as they adapt to cleaner blends and stricter sulphur limits. Analysis of fuels tested by LR’s Fuel Oil Bunkering Analysis and Advisory Service (FOBAS) shows that the vast majority met specification and were fit for purpose – 3.5% of very low sulphur fuel oil (VLSFO) fuel samples were off-spec, but only a small fraction of these were unusable.
VLSFO performance and stability concerns
For example, 0.6% of VLSFO samples exceeded the 0.53% 95% confidence range of the 0.50%m.m MARPOL Annex VI limit. Sediment stability also showed varied performance at major ports, with certain ports facing continued problems while others providing much more stable fuel. Distillate fuels continued to demonstrate predictable behaviour, remaining the premium choice for operations requiring tighter quality control.
Biofuel uptake and regulatory clarity
Sustainability and fuel diversity are key trends in the H1 2025 findings. Uptake of FAME-based biofuel blends, notably B30 RF, is increasing across ports including Singapore, Algeciras and Antwerp. This is being driven by regulatory clarity from MEPC 83 and ISO 8217:2024, which confirmed that blends up to 30% are treated as conventional fuels, simplifying NOx compliance. FOBAS testing to date has found no systemic operational issues with these blends, with most quality considerations linked to the conventional fuel components.
Direct calorific value measurement
The report also notes a growing shift to direct calorific value measurement, using ASTM D240 Bomb Calorimetry, to more accurately account for the lower energy content of biofuel blends. Early adopters report more precise consumption forecasting, improved voyage planning and reduced cost variability.
Impact of new sulphur emission limits
Regulatory change has also continued to shape fuel decisions. From 1 May 2025, the Mediterranean’s designation as a Sulphur Emission Control Area (SECA) brought a 0.10% sulphur limit into force, prompting operators to fine-tune fuel management strategies alongside preparations for EU and FuelEU Maritime requirements.
Shipowners today face a more complex fuel landscape than ever before. Our latest findings show that quality remains high and compliance strong, but also that success increasingly depends on proactive testing, data-driven decision-making and close cooperation between suppliers and operators. This approach will be essential as the industry accelerates its transition to low- and zero-carbon fuels
… said Usman Muhammad, FOBAS Product Manager.
Looking forward, while regulatory updates for biofuels provide a clearer path for their adoption from a NOx compliance perspective, new technical challenges, such as ensuring accurate energy content measurement, must be managed by operators.
Year ahead #1 Mediterranean Sulphur Emission Control Area
On the 1st of May 2025, the requirement for ships operating in the Mediterranean Sea to use fuel with a sulphur content not exceeding 0.10% m/m came into full effect. This confirms that ships operating in the Mediterranean Sea need to comply with regulation 14.4 of MARPOL Annex VI (unless the ship is using a sulphur-oxides abatement technology such as exhaust gas scrubbers). This represents a significant change for many ships and could also affect the types of fuel available at certain ports, so it is essential for operators to have carefully planned for this change.
#2 EU ETS, FuelEU Maritime, and Carbon Intensity Indicator
Along with the new ISO8217 standard there is also the inclusion of the marine industry in the EU ETS (emissions trading system) and, along with other IMO, EU and wider industry pressures, there will likely be more incentive to start switching to biofuels for many vessels and with this a continually growing biofuel supply market.
This will bring challenges in terms of availability and cost, as well as clearly understanding the relevant regulatory requirements, and will also introduce challenges from a fuel quality point of view. As seen in H1 2025, the risk of quality issues and contamination events remains a primary concern that must be managed as new fuel blends enter the market.
#3 Alternative fuels
There of course is also continuing development and progress on zero or near-zero carbon fuels, such as methanol, hydrogen, and ammonia. These new fuels introduce a number of issues to consider but will be important parts of the overall fuel mix going forward and for the foreseeable future alongside traditional marine residual, distillate fuels and drop-in fuels.
