Indianapolis-area regular gasoline rises about 16 cents in a day while Indiana’s state gasoline tax holiday remains in effect.

Gasoline prices climbed sharply across central Indiana heading into Thursday, with AAA reporting an Indianapolis-area average of $3.907 a gallon for regular unleaded — up 16.2 cents from Wednesday and nearly 36 cents from a week earlier.

The increase comes as a shutdown at a major Illinois refinery adds pressure to a fuel market already strained by international supply disruptions. Wholesale gasoline prices in the Midwest rose again Wednesday, providing evidence of higher fuel costs moving through the distribution system.

Indiana’s gasoline tax holiday remains in place. The increase does not reflect the reinstatement of the two suspended state gasoline taxes.

For a driver buying 15 gallons, the Indianapolis-area daily increase amounts to about $2.43 more per fill-up. The increase over the past week adds about $5.38. The national average Thursday was approximately $4.44 a gallon.

The daily comparison confirms a sharp increase between Wednesday’s and Thursday’s readings. It does not establish the exact hour each station changed its signs.

The most immediate regional disruption began Sunday, September 13, when a power outage forced ExxonMobil’s Joliet refinery in Illinois to shut down. ExxonMobil told Reuters that power failed around 3:30 p.m. Central time and returned around 7 p.m. The outage activated safety flares and stopped operations.

Restoring electricity did not mean an immediate return to normal fuel production. Reuters reported Monday that units were being stabilized; industry monitor IIR Energy anticipated normal service by the end of the week. That was an expectation, not confirmation that the refinery had restarted fully.

The plant can produce approximately 11 million gallons of gasoline and diesel daily, according to ExxonMobil information cited by Reuters. A disruption there matters to the broader Midwest fuel market.

GasBuddy petroleum analyst Patrick De Haan also cited maintenance at BP’s Whiting refinery in northwest Indiana as another source of regional pressure, NBC Chicago reported Monday. The overlapping disruptions reduce the region’s flexibility in meeting fuel demand.

Wholesale data help explain why drivers saw another jump this week. DTN’s September 16 market report, carried on HF Sinclair’s customer portal, put the Midwest’s average conventional gasoline terminal price at about $3.47 a gallon, up 13.31 cents from the previous session. Terminal prices are wholesale prices, not the final amount motorists pay.

The same report showed gasoline wholesale prices rising in all five major U.S. petroleum regions even as crude oil futures declined. That distinction matters: the availability and cost of finished gasoline can move differently from the price of the crude oil used to make it.

The U.S. Energy Information Administration explains that refinery and pipeline interruptions can move gasoline prices quickly. Concern about future supplies can prompt wholesalers to bid more for available fuel. Local competition, delivery costs and suppliers also help explain why nearby stations may change prices by different amounts.

The regional problems sit on top of a broader international squeeze. In GasBuddy’s Monday assessment, De Haan pointed to U.S.-Iran tensions, new hostilities in the Red Sea and the shutdown of Saudi Arabia’s East-West pipeline. Attacks on Russian refineries added pressure on global refined-fuel supplies, according to the assessment reported by WBIW.

Indiana’s tax relief cushions those market pressures but does not set a ceiling on pump prices.

For September, the suspended gasoline use tax is 23.9 cents a gallon. The state’s gasoline excise tax rate is 37 cents. Together, the suspended taxes total **60.9 cents a gallon**, or approximately $9.14 on 15 gallons, assuming the full tax reduction is reflected in the retail price. The September total is about 61 cents rather than 63 cents; the use-tax rate is recalculated monthly.

There is a discrepancy in the state’s published expiration dates. Braun’s September 3 announcement described an extension through October 6. However, the signed Executive Order 26-25 states that the emergency continues **through October 5**, and the Department of Revenue says it will not collect the two taxes through that date.

The governor’s office says Braun will reevaluate whether another pause is necessary. Braun first suspended the gasoline use tax in April and added the excise tax in May.

DOR says the suspended taxes are collected at the distributor level, with savings expected to flow through to pump prices. The holiday does not eliminate every gasoline tax or fee: the federal gasoline tax remains, and DOR’s suspension notice excludes the state oil inspection fee.

Normally, the seasonal move toward cheaper winter gasoline helps ease prices. De Haan’s Monday assessment cautioned that ongoing supply disruptions could limit that relief. The timing of refinery recovery and developments in international fuel supplies remain key uncertainties.

The available evidence supports a combination of regional production problems and broader wholesale-market pressure. It does not establish how much of any individual Fishers station’s increase came from each factor, or when that station’s price will come back down.