Updated April 5, 2026 — Prices updated regularly from EIA data
Route • 1 states
About Interstate 66
Running 76 miles from Middletown, VA to Washington, DC, I-66 is a short but heavily congested corridor in the DC metro region. Gas prices along I-66 reflect the high-cost Northern Virginia/DC market.
Interstate 66 passes through several states on its route. Oil-producing states like Texas, Oklahoma, Louisiana, North Dakota, and Wyoming typically offer the cheapest gas along any interstate that traverses them.
The average gas price along Interstate 66's route today blends prices from all the states the highway passes through. This blended average reflects both high-price and low-price state markets along the full corridor.
Interstate 66 spans 1000 miles across multiple states. For a vehicle averaging 28 MPG highway, the fuel cost varies significantly depending on which states and price zones the route covers.
Interstate 66 passes through or near major cities where competitive fuel markets and warehouse clubs offer the best prices. Look for Costco, Sam's Club, or high-volume discount stations in each major metro along your route.
A 2-mile detour to save 20 cents per gallon on a 15-gallon fill-up saves $3. With a car getting 28 MPG, the detour uses 0.14 gallons. Detours above 3-4 miles for savings under 20 cents per gallon are generally not worthwhile.