The rise was the steepest in the Rocky Mountain region, where prices rose 1.7 cents to $4.136 per gallon. Prices inched up in all regions, except in California, where prices fell half a cent to $4.476 a gallon.
Crude oil for May delivery rose $1.52 to $106.87 a barrel on the New York Mercantile Exchange. The increase came amid news that some buyers have halted or curbed imports of Iranian oil because of Westernsanctions.