U.S. refiners last quarter imported West African oil at the highest rate in nearly three years, customs data showed, buying the gasoline-friendly crudes as they boosted motor fuel production to meet summer driving demand.

Imports from West African nations, primarily by East Coast operations of PBF Energy, Phillips 66 and Monroe Energy, were at least 11.6 million barrels in the second quarter, U.S. customs and ship-tracking data on Refinitiv Eikon showed, the highest since the third quarter of 2019.

Imports rose even as prices for Nigeria’s Qua Iboe and Yoho crudes touched record levels. Qua Iboe averaged a $4.20 premium to dated Brent in the quarter.

U.S. gasoline demand has climbed. Consumption of finished motor gasoline reached 9.4 million barrels per day, the highest since the end of 2021, according to the U.S. Energy Information Administration. East Coast gas prices were $4.50 to $5 per gallon.

West African imports spiked in May with 5.2 million barrels being discharged in the U.S., more than doubling from April. Light oil, like that from West Africa, typically produces a greater percentage of gasoline than heavy oil.

“Some refiners have been forced into running more light sweet in lieu of Russian sour,” a seller of West African crude said. The U.S. in March banned imports of Russian crude and refined products over Moscow's invasion of Ukraine, which it calls a “special operation.”

The U.S. share of West Africa light sweet crude imports climbed to about 20% last month, from about 8.2% before Russia’s invasion, said Houston-based independent energy strategist Clay Seigle, citing data from energy analytics firm Vortexa. Asia's share fell to about 23% from 42%.

Imports of Arab light and extra light sour crude grades in June also touched their highest since May 2020, at 19.3 million barrels.