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Cheapest 100LL Avgas in Illinois

19 FBOs with 100LL pricing · Updated daily

Best Price: $5.95/gal

Midwest Aviation at KMWA in Marion

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The average 100LL price in Illinois is $7.85/gal. Below are all FBOs ranked from cheapest to most expensive.

Prices updated daily · Last updated July 8, 2026

100LL Avgas Market Analysis in Illinois

We track 100LL avgas at 19 FBOs across 16 airports in Illinois. The cheapest 100LL is $5.95/gal at Midwest Aviation (KMWA), and the highest is $9.58/gal — a $3.63/gal difference depending on where you stop. 10 FBOs are below the $7.85/gal state average. For a typical 50-gallon piston top-off, the cheapest stop saves roughly $95 versus the average.

100LL is the standard fuel for most piston-engine aircraft. Because avgas volumes are smaller than Jet-A, prices are especially sensitive to local supplier logistics and airport traffic. Self-serve pumps usually undercut full-service by a wide margin and are often available 24/7. Figures update daily from AirNav reports.

Cheapest 100LL in Illinois: FAQ

What is the cheapest 100LL avgas in Illinois?
The cheapest 100LL in Illinois is $5.95/gal at Midwest Aviation (KMWA) in Marion, as of July 8, 2026.
What is the average 100LL price in Illinois?
Across 19 FBOs reporting 100LL in Illinois, the average is $7.85/gal, ranging $5.95 to $9.58/gal.
Where is 100LL cheapest for piston aircraft in Illinois?
Marion (KMWA) has the lowest 100LL in Illinois at $5.95/gal. 10 of 19 FBOs price below the state average.
How often are Illinois 100LL prices updated?
100LL avgas prices in Illinois are refreshed daily from AirNav FBO reports; the most recent update was July 8, 2026. Confirm with the FBO before fueling.

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