Marine biofuel quality verification relies on a comprehensive series of laboratory tests designed to ensure compliance with international standards and […]
LNG (Liquefied Natural Gas) and LPG (Liquefied Petroleum Gas) are distinct liquefied fuels with different chemical compositions, storage requirements, and
The shipping industry has access to several biofuel options that can significantly reduce greenhouse gas emissions. The primary biofuels available
Marine Diesel Oil (MDO) is a blended marine fuel consisting of distillates combined with a small proportion of heavy fuel
Low Sulfur Fuel Oil (LSFO) is a marine fuel with a maximum sulfur content of 0.50% by mass, designed to
Ultra-Low Sulfur Fuel Oil (ULSFO) is a marine bunker fuel with a sulfur content of 0.10% by mass or less,
Intermediate Fuel Oil (IFO) is a blended marine fuel that sits between lighter distillate fuels and heavier residual fuel oils
Marine Gas Oil (MGO) is a distillate fuel used in marine diesel engines and auxiliary systems aboard commercial vessels, naval
Very Low Sulphur Fuel Oil (VLSFO) represents a fundamental shift in marine fuel composition compared to traditional High Sulphur Fuel
Marine fuel selection is a critical part of bunker procurement and operational planning.
Different fuel types vary significantly in composition, performance characteristics, regulatory requirements, and operational risk — particularly in regions where enforcement practices, availability, and blending standards differ from port to port.
This section of the Knowledge Hub provides practical, non-commercial insight into the most commonly used marine fuel types, how they differ, and what vessel operators should consider when planning fuel supply in the Middle East and surrounding regions.
Marine fuel quality is assessed against established technical standards rather than commercial descriptions alone.
ISO 8217 defines the specifications for marine fuels, including parameters such as viscosity, density, sulphur content, and ignition quality, and is widely referenced in bunker supply contracts.
Marine fuels are not defined by commercial naming alone.
Their use is governed by international regulations and technical standards that set limits on sulphur content, emissions, and fuel quality parameters.
At a regulatory level, fuel sulphur limits and emission requirements are established through the International Maritime Organization (IMO) under MARPOL Annex VI, which defines global and regional requirements for marine fuels and air pollution control.
From a technical perspective, marine fuel quality is assessed against internationally recognised specifications.
ISO 8217 defines the parameters used to classify marine fuels, including viscosity, density, sulphur content, ignition quality, and contamination limits. These specifications are commonly referenced in bunker supply contracts and fuel testing procedures.
Together, regulatory compliance and technical specification form the baseline against which marine fuels are evaluated — regardless of fuel type.
Marine fuels can broadly be divided into distillate fuels and residual fuel oils, with several blended products sitting between the two categories.
Distillate fuels such as Marine Gas Oil (MGO) and Marine Diesel Oil (MDO) are refined products with relatively low viscosity and stable combustion characteristics. They are commonly used in auxiliary engines, smaller vessels, and in Emission Control Areas (ECAs) where lower sulphur limits apply.
Residual and blended fuels, including Intermediate Fuel Oil (IFO) and Very Low Sulphur Fuel Oil (VLSFO), are typically used by larger commercial vessels. These fuels vary more widely in composition and may be produced through blending processes, making compatibility, stability, and quality control key operational considerations.
High Sulphur Fuel Oil (HSFO) remains in use where permitted, typically in conjunction with exhaust gas cleaning systems (scrubbers).
In response to tightening environmental regulations and decarbonisation targets, the shipping industry is increasingly evaluating alternative fuels.
Liquefied Natural Gas (LNG) and Liquefied Petroleum Gas (LPG) are already in use in certain vessel segments, each with distinct storage, safety, and operational requirements.
Biofuels, including fatty acid methyl esters (FAME) and other drop-in blends, are gaining traction as transitional fuels, although fuel quality verification, compatibility, and testing procedures remain critical considerations.
Industry guidance on fuel quality testing and operational best practices is often informed by bodies such as the International Bunker Industry Association (IBIA), alongside engine manufacturers and classification societies.
Choosing the appropriate marine fuel involves more than meeting regulatory limits.
Vessel operators must consider:
These factors are particularly relevant in regions with diverse supply chains and varying implementation of international standards.
The articles below examine individual marine fuel types in more detail, including their composition, regulatory context, operational characteristics, and common use cases.
All content is provided for informational and decision-support purposes only.
Gulf-Bunkering does not trade, supply, or physically deliver marine fuels.
Instead, the platform provides independent market insight and regional context, and facilitates contact between bunker buyers and relevant suppliers or service providers where appropriate.
This allows vessel operators to engage with the market from a more informed position before entering direct commercial discussions.
