Chevron Marine Lubricants made its first delivery of a 40 BN Category II lube oil on 30 August, when it supplied a stem of its new Taro Ultra Advanced 40 to SIEM Car Carriers, according to the company's release.
After IMO’s 0.5% 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 became one of the first oil to be 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 oil.
Those development and approval tests took place on vessels with MAN 8G80ME-C9.2 engine burning VLSFO, but Taro Ultra Advanced 40 is also suitable for use with other low-sulphur fuels, such as ULSFO, LNG and methanol. This versatility is crucial for SIEM car carriers, which will be using the oil in the LNG-fuelled MAN ES 7S60 ME-C GI 12,614kW low-speed engines installed in its 7,500-car capacity sister ships, SIEM Aristotle and SIEM Confucius.
These are deep-sea car and truck carriers equipped with dual-fuel engines, designed to operate on LNG and marine gas oil, which helps provide economic efficient operation.
Taro Ultra Advanced 40 joins Chevron’s existing range of Taro Ultra oils, including Taro Ultra 100 and Taro Ultra 140, which are already rated as Category II oils and suitable for use in Mk 9 engines and above, but with higher-sulphur fuels. Chevron’s five-oil Taro Ultra range also includes Taro Ultra 20 and Taro Ultra 70 to cover the full range of fuel sulphur content.
Chevron is one of the world’s leading integrated energy companies.