Pump prices could drop in Michigan after EPA lifts summer-gasoline mandate

• Gasoline prices could be on their way down in Michigan and three other Midwestern states
• The EPA has temporarily waived a mandate to sell cleaner-burning, summer-grade fuel
• The move comes after a refinery shut down in Illinois, causing prices to soar

Drivers in Michigan and three other Midwestern states could see some relief at the gas pump in the coming days. The EPA has temporarily waived its requirement that retailers sell a cleaner-burning grade of gasoline during the summer months.  

The emergency fuel waivers apply to Michigan, Illinois, Indiana and Wisconsin and last through Aug. 20. 

The waivers aim to alleviate supply shortages that have driven up gas prices. Last Friday, the cost of a gallon of regular in Michigan hit $3.81, a record high for the year, according to AAA.

In Illinois, the average price for a gallon of regular gas last week was $4.07. It was $3.66 in Indiana and $3.52 in Wisconsin, which were all above the national average of $3.52. 

Gov. Gretchen Whitmer and the governors of Illinois, Indiana and Wisconsin requested the waivers. “The temporary waiver granted by the EPA will help us keep fuel prices stable, ensuring Michiganders can fuel their cars or heat their homes and businesses at a predictable rate,” Whitmer said in a statement.

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The shutdown of an ExxonMobil refinery in Joliet, Illinois, last month contributed to higher prices. That shutdown was the result of power outage caused by severe thunderstorms and tornadoes that swept through the region. 

The Joliet refinery, roughly 40 miles outside of Chicago, produces nearly 9 million gallons of gasoline and diesel fuel every day, according to the company’s website. While the power has been restored, it could take weeks before it reopens. 

“This extreme and unusual fuel circumstance is the result of an extreme weather event which caused the power outage at ExxonMobil’s Joliet refinery, an event that could not reasonably have been foreseen and is not attributed to a lack of prudent planning on the part of suppliers of fuel to waiver the area,” the EPA said in a letter granting the waivers.

The waiver allows refineries to produce “winter-grade gasoline,” which contains more butane than summer-grade gasoline to help vehicles start up in the colder months. 

Summer-grade gasoline typically contains 2% butane, a colorless, odorless gas used in lighter fluid, for example, according to AAA. The summer blend burns cleaner and contributes less to air pollution, which is more of a threat in hot weather.

Refineries were required to switch to summer-grade gasoline by  May 1, according to the Energy Information Administration. But gas stations in several southeast Michigan counties were required by the Michigan Department of Agriculture and Rural Development to switch to summer-grade fuel by June 1. The switch back to winter-grade fuel takes place on Sept. 15. 

The EPA regulates the “Reid Vapor Pressure,” or RVP, of gasoline sold at retail stations during the summer. RVP measures the volatility of gasoline. The higher the RVP, the faster it will evaporate and contribute to ground-level ozone. Federal rules require the sale of lower RVP gasoline in the summer in Michigan.