You are on board a vessel with a slow speed crosshead type engine. The fuel just received has a significantly lower sulfur content then the previous bunkers. Which of the following would be a concern due to the reduced sulfur content?

Correct Answer: Option B — Base number of the cylinder oil

Switching to a significantly lower sulfur fuel requires adjusting the cylinder oil Base Number (TBN) downward to prevent excessive alkalinity, which can cause calcium ash deposits, piston crown scuffing, and exhaust valve burning. Lubrication management must align directly with incoming bunker sulfur content.