Updated April 5, 2026 — Prices updated regularly from EIA data
Route • 3 states
About Interstate 26
Stretching 353 miles from Kingsport, TN to North Charleston, SC, I-26 traverses the Southern Appalachians and Lowcountry. Gas prices along I-26 are competitive throughout, with South Carolina's low fuel taxes keeping costs reasonable.
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.
The cheapest gas along Interstate 26 is generally found in Tennessee, where lower fuel taxes and proximity to refineries or pipelines keep prices down. Avoid fueling at highway-exit stations in South Carolina, where tourist premiums push prices 15-25 cents above the best nearby rates.
For a trip along Interstate 26, a vehicle averaging 25 MPG would use approximately 1 gallon per 25 miles. At current average prices along the route, budget approximately {perMileCost} cents per mile for fuel. Plan fill-ups in lower-price states whenever possible.
Yes — consistently. Highway-exit gas stations charge 10-25 cents more per gallon than stations just 1-2 miles off the interstate. Whenever possible, exit the highway and drive to a commercial area for competitively priced fuel.
Gas prices along Interstate 26 vary significantly by state due to different fuel tax rates. States like Texas (20 cents/gallon), Missouri (17 cents), and Oklahoma (20 cents) consistently offer the most affordable fuel. Pennsylvania (59 cents) and California (67 cents) are among the most expensive.