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Shell's Solution for Managing Oil Stress

In medium-speed diesel engines, the oil is subjected to acid, thermal and asphaltene stresses. These oil-stress factors can shorten oil and engine component life, and lead to reduced reliability (Table 1).

oil stress

Table 1: The Effects of Oil Stress

  BN Depletion Ring Liner and Valve Wear Piston Undercrown Deposits Ring Grove Deposits Viscosity Increase Crankcase Fouling Fuel Pump Sticking
Acid x x          
Thermal     x x x    
Asphaltene     x x x x x
Effect on your operation Shortens Oil Life Reduces reliability-shortens life of components Shorten life of Piston Crowns Reduces reliability: shortens life of rings and liners Shortens Oil Life Shortens Filter Life Reduces reliability

Our deep oil-stress understanding, which is based on 20 years of research, and the development of oil-stress management technology have resulted in Shell Argina products. 

Reducing Your Operational Costs

Shell Argina oils have set the benchmark in managing oil stress for decades. The latest generation has significantly improved low- and high-temperature deposit resistance, high base number (BN) retention and resistance to viscosity increase.

Controlling costs by maximising oil durability and engine component life

Rising viscosity due to asphaltene stress or depleting BN due to acid stress can require partial or complete oil replacement. This can be costly and inconvenient. Shell Argina oils’ excellent viscosity control (figures 1 and 2) and BN retention (Figure 3) can help to reduce the amount of oil you use by up to 20% compared with competitors’ products, thereby controlling your oil costs. In addition, a more-durable, longer-lasting oil will protect engine components better, thereby helping to reduce maintenance costs.

 argina velocity

Figure 1. The ability of Shell Argina X to handle asphaltene stress is seen in the slow viscosity rise during accelerated engine tests. After 400 hours, Shell Argina X and competitor’s oil A showed a viscosity increase of less than 20%, but more deposits were produced with oil A. Competitor’s oil B suffered a 29% viscosity increase.

viscosity control

Figure 2. In a field trial, Shell Argina X removed the need for regular partial oil replacement in a MAN B&W engine operating under severe asphaltene stress conditions.

viscosity control

Figure 3. Under accelerated engine test conditions, Shell Argina X and oil A took more than 300 hours to deplete from BN40 to BN20. Oil B fell to BN20 in only 232 hours. An oil’s BN depletes as harmful acids are neutralised. However, this depletion can be caused by secondary processes such as oxidation, which leaves the oil unable to protect against corrosion. Shell Argina X’s excellent BN retention helps to extend oil life, thereby reducing the need for partial oil replacement, and increase component life through longer corrosion protection.

Delivering Reliability

Shell Argina oils are designed to manage differing effects of oil stress to reduce downtime, keep your engine cleaner and give longer oil and component life, thereby improving engine reliability. This delivers greater vessel reliability and helps to maximise commercial performance.

  • Greater power to clean and protect. Clean engines are efficient engines. With their increased resistance to fuel oil contamination and physical thickening, Shell Argina oils form fewer deposits as a result of the thermal and asphaltene stresses in heavy-fuel engines.
  • Better general engine cleanliness. Fewer crankcase and valve-deck deposits help to prolong filter life and reduce cleaning maintenance. A clean crankcase also indicates that the less visible engine parts are in good condition. Field trials have demonstrated the improved general engine cleanliness with Shell Argina oils, thanks to its increased resistance to oil stress, which results in fewer deposits.
  • Improved piston cleanliness. In field trials, Shell Argina oils demonstrated visible improvements in ring belt cleanliness, which can help to prevent ring sticking, blow-by and liner damage.

Choose Shell Argina to enjoy Peace of Mind

Shell Argina oils are designed to cope with differing aspects of oil stress and have proven performance that can help to cut costs, increase reliability and, ultimately, along with our technical services and our port network give you greater peace of mind.

For effective overall oil stress management

effective overall oil stress management

Of the products we tested, only Shell Argina oils offered top performance against all oil stresses.

Approved by engine manufacturers

Shell Argina oils are approved by major engine manufacturers, including Caterpillar (MaK), MAN B&W and Wärtsilä.

Products for Medium Speed Engines


Product Table
Product Description Viscosity,
mm2/s AT
number mg/KOH/g
kg/m3 at
    40°C | 100°C        
Shell Argina S 40 Lubricant for medium speed diesel engines operating on low sulphur blended fuels and low oil stress conditions 135 | 14 20 234 -18 909
Shell Argina T 30 Lubricant for highly rated, medium-speed diesel engines operating
on residue fuel under moderate oil stress conditions
110 | 12 30 212 -18 918
Shell Argina T 40 Lubricant for highly rated, medium-speed diesel engines operating
on residue fuel under moderate oil stress conditions
135 | 14 30 225 -18 921
Shell Argina X 40 Lubricant for highly rated, medium-speed diesel engines operating
on residue fuel under high oil stress conditions
135 | 14 40 205 -18 916
Shell Argina XL 40 Lubricant for highly rated, medium-speed diesel engines operating
on residue fuel under very high oil stress conditions
135 | 14 50 229 -18 921

Optimise Your Operations with Technical Services

  • Lubricant advice can help you to select the right lubricant grade to deal with the specific level of oil stress in your engine.
  • Shell Rapid Lubricants Analysis is an oil condition monitoring service that helps your vessels to run smoothly by identifying potential oil or equipment failures before they become critical.
  • Shell’s Oil Life Extension Tool offers more customised specific advice for optimising expenditure on trunk-piston-engine lubricant.

Watch what our customers have to say about Shell Argina!