Diesel Prices in Illinois Today
Average diesel price in Illinois: $6.828 per gallon on September 22, 2026. U.S. average $6.529. Updated daily.
What is the price of diesel in Illinois today?
Diesel in Illinois averages $6.828 per gallon today (September 22, 2026), $0.299 more than the U.S. average of $6.529. Illinois ranks #44 of 51 for cheapest diesel (1 = cheapest). A loaded semi at about 6.3 mpg spends about $1.08 per mile on fuel in Illinois.
per gallon today
U.S. average $6.529
of 51 (1 = cheapest)
semi truck, today
Fuel cost per mile in Illinois
Estimated diesel cost at today's Illinois price of $6.828 a gallon, using fuel economy calibrated to FHWA and NACFE data.
| Truck | Fuel per mile | Fuel per 1,000 miles |
|---|---|---|
| Dry Van38,000 lbs, ~6.3 mpg | $1.09 | $1,086 |
| Reefer38,000 lbs, ~6.0 mpg | $1.13 | $1,131 |
| Flatbed40,000 lbs, ~6.0 mpg | $1.13 | $1,129 |
| Hotshot12,000 lbs, ~8.9 mpg | $0.77 | $767 |
| Box Truck7,000 lbs, ~9.1 mpg | $0.75 | $748 |
Your numbers depend on load weight, speed, terrain and idling. Enter them in the truck fuel cost calculator for an exact estimate.
Frequently asked questions
What is the price of diesel in Illinois today?
Diesel in Illinois averages $6.828 per gallon today (September 22, 2026), $0.299 more than the U.S. average of $6.529. Illinois ranks #44 of 51 for cheapest diesel (1 = cheapest). A loaded semi at about 6.3 mpg spends about $1.08 per mile on fuel in Illinois.
How much does it cost to fill a semi truck in Illinois?
At $6.83 a gallon, 150 gallons of diesel costs about $1,024 and 200 gallons about $1,366 in Illinois today.
Is diesel cheaper in Illinois than nearby states?
Among nearby states in the same region, the cheapest today is Oklahoma at $6.029 a gallon. Illinois is $6.828.
How often are Illinois diesel prices updated?
Every day. This page refreshes each morning from daily state averages, with the EIA weekly survey as a backup.
| Oklahoma | $6.029 |
| Tennessee | $6.215 |
| Nebraska | $6.231 |
| North Dakota | $6.239 |
| Kansas | $6.249 |
| South Dakota | $6.277 |
Source: AAA daily state average, September 22, 2026. All 50 states
Running freight through Illinois?
Texas Solutions dispatches semis for 5%, hotshots for 8% and box trucks for 10% of weekly gross. We plan lanes to cut empty miles and fuel.