Description:

Medium-speed trunk-piston diesel engine oil.

Shell Argina XL is a multifunctional crankcase lubricant for highly rated medium-speed diesel engines operating on residual fuel. Argina XL is designed for conditions of very high oil stress and has been further optimised to improve deposit control.  

Applications:

Medium-speed industrial or marine propulsion and auxiliary engines, burning residual fuel oils, which create conditions of very high oil stress. These conditions usually occur:

- in newer engine designs, with flame rings, especially from Wartsila,

- where oil consumption is <0.5g/kWh - where load factors are >90%

- where fuels with sulphur >3% are in use 

Medium-speed engines burning residual fuel need very specialised lubricants. Heavy fuels contaminate the oil with asphaltenes, requiring special types of detergency to avoid sludges. The combustion of high sulphur fuels produces sulphur acids, which cause high wear rates of piston rings and cylinder liners unless neutralised by a high basicity reserve in the oil. The oil is in service for very long periods, so centrifugal separators are used to remove water and combustion contaminants from the oil. Medium-speed engine oils must be specially designed to release these contaminants in the separator.

Modern engines are more demanding than ever. Oil consumption has been drastically reduced by the use of "flame" or "anti-polishing" rings. Lower oil consumption reduces the rate of renewal of the oil through top-up. This means that the average age of the oil charge is far greater than it used to be. Consequently the oil is exposed for much longer than before to the stresses of high temperatures, contamination and acid combustion by-products. Argina XL has been specially designed for very high stress conditions, found most often in modern Wartsila engines in power plant or ship propulsion applications. 

Performance Features:

• Excellent engine cleanliness

Higher detergency than even Argina X, leading to exceptionally clean crankcase, valve deck and pistons. The formulation has been further optimised to reduce deposits in critical areas, e.g. piston undercrown.

• Very high oxidation resistance

Longer oil life and greater resistance to oxidative thickening.

• Extra high Base Number (50)

Longer oil life in engines where life is limited by depletion of Base Number (BN). In many cases a satisfactory equilibrium BN level can be maintained, in conditions where this would be impossible with a 40BN oil.

• Very good Base Number retention

Resists secondary loss of Base Number due to oxidation.

• Suitability for centrifugal separators

high detergency/low dispersancy formulation releases contaminants and water readily in centrifugal separators.

• Full compatibility with Argina family

Argina XL can be used to top up engines already running on any other member of the Argina family, giving immediate control of BN without the need for an oil change.