Cheapest Gas in Rockford, IL

Updated May 20, 2026 — Prices updated regularly from EIA data

$3.44

Lowest price at Costco in Rockford

Finding Cheap Gas in Rockford

Gas prices in Rockford, Illinois vary significantly by brand and location. This guide identifies today's most affordable options — potentially saving the average driver $$12.00 or more annually.

Maximum Savings in Rockford

Choose Costco over Chevron

$0.25 per gallon

$3.75 per 15-gallon fill • $12.00 per year (est.)

Cheapest Brands in Rockford

Rank	Brand	Est. Price	Savings vs. Most Expensive
#1	Costco	$3.44	$0.25
#2	Speedway	$3.56	$0.13
#3	Circle K	$3.57	$0.12
#4	Sunoco	$3.60	$0.09
#5	Marathon	$3.61	$0.08
#6	BP	$3.63	$0.06
#7	Mobil	$3.64	$0.05
#8	Exxon	$3.65	$0.04
#9	Shell	$3.67	$0.02
#10	Chevron	$3.69	$0.00

Gas Saving Tips for Rockford Drivers

Check tire pressure monthly, especially as seasons change — tire pressure drops about 1 PSI for every 10-degree Fahrenheit temperature decrease.
Fill up on Monday or Tuesday mornings — gas prices typically rise Thursday through Sunday as weekend demand increases, then reset lower early in the week.
Use the GasBuddy or Waze app to compare prices within 5 miles of your location before every fill-up. Even a 10-cent difference on 15 gallons saves $1.50 each fill-up.
Join a warehouse club (Costco, Sam's Club, BJ's) — their fuel consistently runs 10-25 cents below local market prices. The membership cost typically pays for itself in fuel savings within the first two months.
Sign up for gas station loyalty apps — Shell Fuel Rewards, Marathon MakeItCount, and Circle K Inner Circle all offer genuine per-gallon discounts that compound over time.