Problems attributed to marine fuel quality are increasing. Important factors influencing fuel quality are the type of crude oil refined and the refining processes it undergoes. Conversion steps such as visbreaking and catalytic (cat) cracking concentrate the less desirable characteristics in bunker fuel oil. Therefore, proper shipboard treatment of marine residual fuels is essential for reliable and efficient engine performance.
Intermediate marine residual fuels are still ordered by viscosity alone, but the work on international specifications for marine fuels is nearing completion. BSMA 100:1982 was published by the British Standards Institution (BSI) in 1983, and work is nearing completion by the International Organization for Standardization (ISO) on international standards. As a common reference, standards will be valuable, and their eventual adoption by the trade in the purchase and sale of bunkers is likely.