Retail gasoline in the US slid to the lowest level in almost four months as refineries boosted production.

Pump prices averaged $3.593/gal this week, down 4.2 cents from the previous week and the lowest since March 31, data posted on the Energy Information Administration’s website show. Gasoline was 2.4% below 2013 levels.

Travelers and commuters are seeing relief at the pumps as US refiners process a record amount of crude oil. A production boom from US shale formations and Canadian oil sands pushed some domestic crudes down last month to multi-year seasonal lows versus foreign grades. US and international benchmark oil prices have retreated as production in Iraq has been unaffected so far by unrest there.

“Refineries are running really smoothly right now and they’re making lots of gasoline,” Michael Green, a spokesman for Heathrow, Florida-based AAA, said by telephone from Washington. “There’s also a stalemate in Iraq that’s helped stabilize the markets because there’s less fear that rebels will disrupt oil production and exports.”

Refinery crude runs in the US climbed to 16.6 million bpd in the week ended July 11, the most in Energy Information Administration data going back to 1989, and plants operated at 93.8% of capacity, the highest level since August 2005.

The surge in US plant rates narrowed gasoline’s crack spread versus West Texas Intermediate crude on the New York Mercantile Exchange, a rough measure of refining profit, last week to $17/bbl, the smallest in five months and the lowest seasonally in four years. The gap was $17.77 on Tuesday. The motor fuel’s premium to the international standard Brent oil shrank to $11.89, before rebounding to $12.96.

Watching Gulf

Retail gasoline may “drift down slowly by a few more cents” should refineries in the US continue to run at high rates and hurricanes steer clear of the Gulf, Green said. The six-month Atlantic storm season runs from June 1 through Nov. 30, with the statistical peak Sept. 10 and the most activity from mid-August to mid-October.

The second tropical system of the season formed far east of the Lesser Antilles island chain on Monday, the National Hurricane Center’s website shows.

The escalating tension between the West and Russia, the fighting in the Gaza Strip, and the violence in Iraq will temper the decline in the pump price, said Andy Lipow, president of energy consulting firm Lipow Oil Associates in Houston. Both Brent and WTI capped their first increases last week in a month on the conflicts.

“I expect the retail price to go down to about $3.55 a gallon over the next week or so,” Lipow said. “Then we’ll have to see if these events overseas result in the market turning around and costing the consumer more money.”

Crude Demand

In the US Midwest, crude demand surged 5.4% and refineries used oil from North Dakota and Canada to run at a record 100.3% of normal operating capacity, EIA data show.

Those grades are getting cheaper relative to their counterparts as hydraulic fracturing and horizontal drilling help draw record volumes of crude out of shale formations. The tight-oil boom has boosted domestic production to the highest level since 1986, turning the US into the world’s largest producer.

Western Canada Select, a heavy, sour blended crude, was unchanged versus WTI at a $24.50/bbl discount, its lowest level for this time of year since at least 2008, data compiled by Bloomberg show. Oil from North Dakota’s booming Bakken shale formation was $7.80/bbl below WTI.

This week, pump prices fell in all regions of the US, with the biggest drop seen in the Gulf Coast region, where it declined 4.6 cents to $3.394/gal. The smallest decrease was in the Rocky Mountain area, which lost 0.4 cent to $3.64.

The EIA collects information from about 800 filling stations as of 8 a.m. local time on Mondays.