After the IMO’s 0.50% sulphur cap came into effect on 1 January 2020, MAN ES defined two performance standards for lube oils intended for use in its two-stroke engines. Existing oils were dubbed Category I lubes and can be used in MAN ES Mk 8 and earlier engines, but it set a higher Category II standard for Mk 9 and later engines.

With less sulphur in the fuel, lubes with lower base numbers would be needed, but they also had to match or exceed the cleanliness achieved when using typical two-stroke lubes of around 100-140 BN. Until suitable 40 BN oils were developed, MAN ES advised operators to alternate between 100 BN and 40 BN oils, based on scavenge port inspections and its analysis of oil drainage samples.

In April 2022, Taro Ultra Advanced 40 was granted a ‘no-objection letter’ (NOL) by MAN ES, confirming that it can be used continuously, without the need to switch to high-BN lubes. This reduces operational complexity for ships’ engineers and removes the need to carry multiple grades of lube oil.

Chevron Global Marine Lubricants’ General Manager Pat McCloud says: “We have been working with our supply chain to set up blending and supply of the product and it is now one of the first 40 BN category II lubricants to be available in major shipping hubs in commercial volumes.”