Wheaton drivers are paying close to $4.83 per gallon for regular unleaded, roughly 60 cents more than the national average, as a chain of refinery breakdowns less than an hour south continues to squeeze fuel supplies across the region.

The Chicago metro average for regular gas hit $4.83 on Oct. 22, according to AAA. The national average stood at $4.27. Illinois diesel averaged $6.56 per gallon, down from a record $6.83 on Sept. 23 but still nearly 80% higher than a year ago. DuPage County regular gas had averaged $4.30 per gallon for the week ending Sept. 5, according to the DuPage Policy Journal. That was before the worst of the refinery problems hit.

Three overlapping refinery disruptions across the Great Lakes region are behind the spike, according to RE Journals.

The ExxonMobil refinery in Joliet, a 275,000-barrel-per-day plant in Will County that produces roughly 11 million gallons of gasoline and diesel daily, suffered a total power outage on Sept. 13. The plant's safety system triggered an emergency shutdown, and flames and black smoke from its flare system were visible on site, according to industry publication ChemNet. That single facility accounts for about 6% of all Midwest refining capacity, feeding pipelines into Illinois, Indiana, Iowa, Michigan and Wisconsin.

ExxonMobil had not finished recovering when a new problem struck. On Oct. 20, the company shut a 50,000-barrel-per-day catalytic reformer at the same Joliet plant after Wood Mackenzie observed decreased stack activity and elevated flaring, Texas Energy Report reported. An ExxonMobil spokesperson said Oct. 21 the company was working to resolve an operational issue but gave no restart timeline.

The Joliet outages coincided with planned maintenance at the Cenovus refinery in Lima, Ohio, which took another 185,000 barrels per day offline starting in September, according to RE Journals. The BP Whiting refinery in Indiana, the Midwest's largest, has also been running with restricted capacity. About 800 BP workers have been locked out since March 19 in a contract dispute with the United Steelworkers, In These Times reported.

Costs ripple beyond the pump

The Bureau of Labor Statistics reported that gasoline prices in the Chicago-Naperville-Elgin area, which includes DuPage County, rose 6.3% from August to September. Year over year, the gasoline index climbed 28.9%.

Gov. JB Pritzker declared all of Illinois a diesel disaster area in early October, directing the Illinois Department of Revenue and State Police not to impose penalties for selling or using tax-exempt, red-dyed diesel fuel through Dec. 31, ABC 7 reported. Nate Harris, CEO of the Illinois Fuel and Retailer Association, told ABC 7 he was skeptical the move would help, warning that retailers face unclear criminal-liability rules at both the state and federal levels.

Suburban school districts that run their own bus fleets have been among the hardest hit, the Chicago Tribune reported. Naperville Unit District 203, which operates more than 120 diesel buses for roughly 16,000 students, expects to spend an extra $300,000 on fuel during the 2026-27 school year if diesel prices hold. No comparable estimate has been published for Wheaton CUSD 200.

When prices might ease

Patrick De Haan, head of petroleum analysis at GasBuddy, told the Tribune that diesel prices may decline slightly in the weeks ahead as the Joliet plant resumes operations. Per-gallon diesel had already dropped more than 25 cents since the Sept. 23 peak.

Longer-term relief is uncertain. "A lot of that is a function of the continued evolution in the situation between the U.S. and Ukraine, and the U.S. and Iran," De Haan told the Tribune. "If we see some improvement in tensions there, then we could see some relief."

The Oct. 20 catalytic reformer shutdown at Joliet complicates the forecast. ExxonMobil has not disclosed a restart date for the unit.