US blender Pennzoil Quaker State was the US’ largest base oils importer in May for the first time in four months.

The blender displaced SK Lubricants Americas, which had been the largest base oils importer during each of the previous three months.

Its share of base oils imports rose for a third month to more than 24pc of the total in May, according to the EIA. The share was up from more than 23pc the previous month and the highest this year.

SK Lubricants Americas was the second-largest importer in May. Its share of base oils imports accounted for more than 22pc of the total. The share was down from just under 24pc in April.

US base oils imports rose in May to a six-month high of 1.51mn bl, according to the EIA.

The imports consist mostly of Group III base oils. The trend reflects the US’ scant Group III production capacity and reliance on imports to cover its requirements for those grades.

Qatar was the source of the largest volume of supplies in May.

Global products supplier and distributor Penthol was the US’ third-largest base oils importer in May, with a share of more than 15pc. It had imported no supplies the previous month. Penthol is the exclusive distributor of ADNOC’s Group III base oils in the US.

Petro-Canada America was the fourth-largest importer. Its share of imports fell to less than 11pc of the total volume in May, from more than 13.5pc the previous month.