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Shell Marine has unveiled its "next-generation" Shell Argina and Shell Gadinia trunk piston oils for the medium-speed engine market.

The Shell Argina range includes four grades: the BN20 Shell Argina S2 for residual, blended and distillate fuels; the 'mainstream' Shell Argina S3 (BN30) and Shell Argina S4 (BN40); and Shell Argina S5 (BN55) - which is designed to offer extra protection from deposits and extended oil life.

Meanwhile, Shell Gadinia S3 is a new addition to the existing standard and anti-lacquer Gadinia variants, and has been developed to control oil consumption in modern engines burning distillate fuels. It is said to have a comprehensive set of non-engine approvals for a wide range of non-engine shipboard applications, to provide a single long-term lubricant solution for smaller vessels working in the most severe operating conditions.

According to Shell, "exhaustive" in-engine trials at its Marine and Power Innovation Centre in Hamburg confirm Shell Argina and Shell Gadinia as oils that avoid sludge formation, improve piston and crankcase cleanliness, and thus block deposit formation.

Both oil types are said to offer improved detergency over previous Shell Marine products and those from competitors.

"Compared with a high-performing industry reference oil, the new Shell Argina S5 shows a 12.6% improvement in BN retention and a 15-20% improvement in piston undercrown deposit thickness, for example," explained Marcus Schaerer, Shell Marine Global Marketing Manager. "For operators, this can translate into lower operating costs via longer oil life, less sweetening and reduced maintenance."

Newer generation engines

Shell believes demand for distillates and low-sulphur heavy fuel oil will only increase as shipping approaches a global cap on fuel sulphur content of 0.5%, imposed by IMO from 2020. Already, dual-fuel engines are taking an increasing share of the medium speed market.

Newer generation engines are designed for better fuel economy and lower operating costs, achieved by higher brake mean effective pressure and higher operating temperatures, Shell notes.

"These characteristics pose a challenge for trunk piston engine oils, increasing the risk of rapid BN depletion and increased viscosity," explained Schaerer.

"The new Shell Argina and Shell Gadinia oils feature excellent BN retention and viscosity control to address the faster oxidation that leads to deposit formation or lubricant contamination, without resorting to unnecessary oil sweetening."