Outage at BP's Whiting refinery, one of the largest in the nation, ends streak of lower gasoline prices nation-wide, AAA finds. File Photo by UPI/John Angelillo | License Photo

WASHINGTON, Aug. 18 (UPI) -- An outage at BP's refinery in Whiting, Ind., pushed retail gasoline prices up for nearly a week straight, snapping a 27-day streak of declines, AAA said.

Motor club AAA reports a national average retail price for a gallon of regular unleaded gasoline at $2.66 for Tuesday, down a fraction of a cent from Monday but up 8 cents from one week ago. Prices in three Great Lakes states skyrocketed overnight last week after BP reported an outage at its Whiting refinery, one of the largest in the nation.


"Motorists in the Midwest are familiar with volatile prices during the summer driving season, yet it is very rare to see the magnitude of the price jumps that occurred over the past week, particularly in Indiana, Illinois, Michigan, Ohio and Wisconsin," the motor club said in a weekly retail status report.

BP's refinery produced around 430,000 barrels of refined petroleum products per day and the Aug. 8 shut down of a crude oil distillation unit has severely impacted regional supplies. AAA said this issue could take at least a month to resolve.

AAA said motorists in Illinois, Indiana and Michigan, the three states most impacted by the outage, saw their gas prices increase by an average of 55 cents over the last week. For Tuesday, Illinois reports a state average price of $3.16 per gallon, 50 cents above the national average.

BP spokesman Brett Clanton said in an emailed statement the rest of the refinery was operating as normal, though no updates on the return to full service were provided.

"BP's supply and logistics organization continues to address the shortfall by acquiring additional supplies of fuel for its customers and, to date, BP has met all of its contractual obligations," he said.

AAA said gas prices by the end of September should drop dramatically because, by then, people will be driving less and refiners will have switched to a winter blend of gasoline, which is cheaper to produce.

Low crude oil prices for 2015 are in part behind the drop in gasoline prices. The national average for Tuesday is about 80 cents below this date in 2014. South Carolina has the lowest state average price in the nation at $2.18 per gallon.