Michigan Gas Prices Hit Highest Year-Over-Year US Increase

Michigan has experienced the largest year-over-year increase in retail gasoline prices in the United States, with surges between 55% and 56.6% as of September 2026. The state's average for regular unleaded gas reached $4.84 per gallon, significantly exceeding the national average of $4.47. Diesel prices in the state spiked even more sharply, rising 86.3% over the past year.

AAA-The Auto Club Group and GasBuddy attribute these increases to global oil market volatility, wars, pipeline outages, and regional refinery issues. A primary driver in the Midwest is a continuing outage at the ExxonMobil Joliet Refinery in Illinois. In contrast, neighboring Indiana has maintained lower prices by temporarily suspending its Gasoline Use Tax and Gasoline Excise Tax.

Nationally, the cost of fuel has risen significantly. Americans have spent an additional $116.1 billion on gasoline and diesel since March 1 compared to the previous year.