MAN Energy Solutions (MAN ES) recommends the use of Category II cylinder oils in its Mark 9 and newer two-stroke marine engine designs; the principal qualifying requirement is centred around piston and ring pack cleanliness. Before it can receive Category II status, a cylinder oil is thoroughly tested by the leading engine designer.

But the situation is more complex than it seems. When the standard was first introduced, 100-plus BN cylinder oils were referred to as Category II oils. However, for engines running on low sulphur fuels or LNG, MAN ES has stated that a 40BN formulation is desirable. As a result, many vessel operators are currently using a combination of Category I 40BN and Category II 100BN cylinder oils in alternating patterns, based on guidance from MAN ES, to meet the required cleanliness performance. This is far from ideal as it creates unwelcome operational complexities and also the need to carry more than one cylinder oil.

To help streamline vessel operations, safely and efficiently, ExxonMobil has added a 40BN Category II cylinder oil into its MobilGard™ offer, Mobilgard™ 540 AC, which has already received a No Objection Letter from MAN ES. The oil is engineered using ExxonMobil’s proprietary balanced formulation approach and has passed stringent fit-for-use assessments. Importantly, it offers a single solution for use with 0.10%, 0.50% sulphur fuels and LNG, helping vessel operators optimise their inventory.

Evolving cylinder oil requirements

Of course, the IMO’s ambition to reduce the carbon intensity of international shipping by at least 40% by 2030, and 70% by 2050, compared with a 2008 baseline, will likely result in the need for additional cylinder oils as new fuel formulations are introduced and engine designs evolve.

Cross-sector collaboration will doubtless offer the most reliable routes to success as sharing data and insights about emerging cylinder oil challenges will help ensure an integrated transition to a lower carbon future for the marine industry. That’s why ExxonMobil is already working with engine designers to create tomorrow’s cylinder oil formulations, today.

Click here to discover more about Mobilgard 540 AC, the latest addition to ExxonMobil’s trusted MobilGard family.