Illinois diesel prices today
Illinois diesel prices todayDiesel averages $6.72 a gallon in Illinois on 2 October 2026 — the 7th most expensive of 51 states, and down $0.10 on the week.
Illinois against the other states
$0.36 a gallon above the unweighted mean of AAA's 51 state averages ($6.36). The cheapest diesel is in Texas at $5.79, the dearest in California at $8.38.
Regular gas in Illinois is $4.70, so diesel costs $2.02 more per gallon — and more than premium at $5.86.
Tax on a gallon of diesel
$0.24 federal + $0.75 Illinois · 2nd highest of 51. The rest — about $5.73 — is the fuel itself, refining, distribution and the retailer’s margin.
Rates as of 1 January 2026. Local taxes, where they apply, are not included.
Diesel prices by city in Illinois
AAA's diesel averages for 16 Illinois metro areas, cheapest first — $0.42 a gallon between the two ends.
| Metro area | Diesel | vs state |
|---|---|---|
| Quincy | $6.50 | −$0.22 |
| Springfield | $6.61 | −$0.11 |
| Rockford | $6.67 | −$0.05 |
| Moline & Rock Island | $6.68 | −$0.04 |
| Decatur | $6.68 | −$0.04 |
| Lake County | $6.68 | −$0.04 |
| Champaign & Urbana | $6.70 | −$0.02 |
| Carbondale & Marion | $6.70 | −$0.02 |
| East Saint Louis | $6.71 | −$0.01 |
| Danville | $6.74 | +$0.02 |
| Elgin | $6.74 | +$0.02 |
| Bloomington & Normal | $6.75 | +$0.03 |
| Chicago Metro | $6.75 | +$0.03 |
| Kankakee & Bradley | $6.76 | +$0.04 |
| Peoria & Pekin | $6.79 | +$0.07 |
| City of Chicago | $6.92 | +$0.20 |
Show the data as a table
What a diesel fill-up costs in Illinois
- Diesel car or SUV — 18 gal$120.94
- Heavy-duty pickup — 34 gal$228.45
- Box truck — 60 gal$403.14
- Semi truck, two tanks — 250 gal$1,679.75
Diesel in neighbouring states
More for Illinois
Frequently asked questions
How much is diesel in Illinois today?
$6.72 a gallon, AAA's Illinois average for 2 October 2026 — the 7th most expensive of 51 states. Regular gasoline is $4.70, so diesel costs $2.02 more per gallon.
Are diesel prices going up in Illinois?
Diesel is down $0.10 (1.5%) on a week ago, and up $2.97 on a year ago, when it was $3.75, on AAA's own earlier averages.
Where is diesel cheapest in Illinois?
Of the 16 metro areas AAA reports in Illinois, Quincy has the cheapest diesel at $6.50 a gallon and City of Chicago the dearest at $6.92. Individual stations vary around these averages.
How much is the diesel tax in Illinois?
$0.99 a gallon: $0.24 federal plus $0.75 in Illinois state taxes and fees, the 2nd highest of 51. The state average is $0.36. Rates as of 1 January 2026.
Is diesel cheaper in a neighbouring state?
Yes — Iowa ($6.09, $0.63 less), Missouri ($6.13, $0.59 less), Kentucky ($6.23, $0.49 less), Wisconsin ($6.37, $0.35 less). On a 100-gallon fill that is up to $62.70; whether it is worth the drive depends on how far the border is.