Very low-sulphur fuel oil (VLSFO) global viscosity levels hit a new record high in the third quarter of 2025, according to the most recent data from French classification society Bureau Veritas.
VLSFO viscosity levels at 50°C (122°F) averaged 190 centistokes (cst) in the third quarter, exceeding the record set in the previous quarter since Bureau Veritas began collecting this information in 2020. The third quarter 2025 average was up by 15pc compared with the same period last year at 165 cst.
Gothenburg, Sweden, had the highest average viscosity at 336cst followed by Skagen, Denmark, at 323cst and Zona Comun, Argentina, at 300cst, Bureau Veritas said.
New Orleans, Louisiana; and Santos, Brazil, once again had the lowest average VLSFO viscosity at 83cst and 94cst, respectively. Yeosu, South Korea, was the third-lowest average viscosity at 118cst, according to Bureau Veritas.
The higher the viscosity level, the less wear and tear will occur in a ship's engine.

