Diesel prices reach record high in metro-east. How much more does gas cost in IL?
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- Illinois ranked 14th in SmartAsset’s May 6 analysis of gas price burden.
- Average Illinois gasoline price was $4.971 per gallon as of May 12, 2026.
- Average diesel prices were at record highs in East St. Louis and statewide as of May 12.
Illinois is among the top 15 states most affected by increased gas prices, according to one recent analysis.
Financial company SmartAsset’s May 6 report, “The Gas Price Burden — Where Gas Prices Hit Hardest,” found Illinois was the 14th state in the U.S. for the cost of a 15-gallon tank of gas compared to typical weekly incomes.
The average price of a gallon of gas in Illinois was $4.971 as of May 12, according to travel company AAA, up by $0.582 compared to one month ago, with a $1.567 increase from one year ago.
St. Clair County drivers typically pay a little less than the state’s average, at $4.869, according to AAA data. In East St. Louis, the May 12 average price of $4.904 is creeping toward the city’s highest recorded average price for unleaded gasoline, which AAA reports was $5.183 on June 14, 2022.
Average diesel prices are at a record high in East St. Louis and statewide as of May 12, according to AAA, at $6.016 for the city and $6.068 across Illinois.
Why are gas prices so high right now?
The primary reason gas prices have seen such a steep increase is the United States’ war with Iran, which has led to an Iranian blockade of the Strait of Hormuz, a critical shipping route for the world’s oil.
Another important factor in Illinois’ gas prices is the state’s gas tax, which is higher than most states’. Through June 30, the Illinois Motor Fuel Tax rate is set at 48.3 cents per gallon of gasoline and 55.8 cents per gallon of diesel, though the rates are tied to inflation and are likely to increase July 1.
From 2018 to 2019, the Illinois gas tax saw a steep increase from 19 to 39 cents under the Rebuild Illinois Capital Program, a $25 billion-plus infrastructure investment plan.
The national average price per gallon of gas was $4.504 as of May 12, according to AAA.
Which states are most affected by increased gas prices?
Here’s how the top 15 states compared, ranked by the cost of 15 gallons of gas as a percentage of each state’s estimated median weekly household income, from SmartAsset:
1. West Virginia, 5.23% of median weekly income needed to buy 15 gallons of gas
2. Ohio, 5%
3. Michigan, 4.97%
4. Indiana, 4.96%
5. Mississippi, 4.86%
6. Kentucky, 4.83%
7. Louisiana, 4.73%
8. Nevada, 4.71%
9. Arkansas, 4.62%
10. Oregon, 4.56%
11. New Mexico, 4.54%
12. California, 4.51%
13. Alabama, 4.39%
14. Illinois, 4.38%
15. Oklahoma, 4.34%
How can you save at the pump?
Auto club AAA offers an online tool where you can search for gas stations along your route, including pricing. GasBuddy is another option, offering an app to search for cheaper gas and a U.S. gas price map. As of May 12, GasBuddy showed crowdsourced prices of $4.99 at several Belleville gas stations, including a Motomart, ZX and BP. A Circle K at 2709 W. Main St. had a listed price of $4.79, and another Circle K, at 8300 Old St. Louis Road, was listed at $4.89.
The app Upside offers cash back on gas purchases, as well as a map to locate the most affordable stations near you.
More money-saving tips to consider include using any cash-back offers your credit card company may have, checking if your company reimburses you for work trips, downloading gas station apps for offers and buying your gas with cash.
Additionally, if you happen to live near a Metro station, public transportation can be a more affordable alternative to driving.
Do you have a question about the Illinois economy for the News-Democrat? We’d like to hear from you. Fill out our Metro-east Matters form below.
This story was originally published May 12, 2026 at 10:41 AM.
