Supply recovered across most major markets, while buyers became more cautious as crude oil prices fell and disruption risks eased.
South Korea increased exports to the US but cut volumes to India, pointing to a shift in demand rather than a shortage of supply.
Taiwan's exports rebounded and Singapore's exports began recovering, reinforcing signs of improving Asian availability.
Europe continued exporting large volumes in April despite disruption-related stock-building, pointing to supply that remained structurally sufficient.
US exports to Europe and South America surged to multi-year highs in April, helping keep Group II markets well supplied despite strong domestic demand.
Group III remained the exception, with Europe and the US still unable to fully replace lost Middle East volumes despite higher shipments from alternative suppliers.
US base oils producer prices recorded their fastest rise in more than a decade in May even as crude oil fell, exposing a widening disconnect between energy and lubricant feedstock markets.