South Carolina Gas Prices and Why They Are What They Are

Prices as of July 21, 2026, per AAA · Updated July 21, 2026

As of July 21, 2026, regular gasoline in South Carolina averages $3.70/gallon (the 12th-lowest in the U.S.), per AAA — 0.30 below the national average of $4.00. Diesel averages $5.02. State fuel taxes and fees add 28.8¢/gallon on top of the 18.4¢ federal excise.

Regular
$3.70
#40 of 51 (1 = highest)
Diesel
$5.02
July 21, 2026
State fuel taxes
28.8¢/gal
Tax Foundation, 2026
U.S. average
$4.00
EIA, week of July 20, 2026

Where the $3.70 goes

Component$/gallonShareSource
Crude oil (national cost, WTI June 2026) 2.02 55% EIA
Federal + South Carolina fuel taxes (18.4¢ + 28.8¢) 0.47 13% Tax Foundation
Refining, distribution, margins & embedded program costs (residual) 1.21 33% computed

Crude oil costs every state's refiners roughly the same, so South Carolina's position comes from the tax line and the residual: refining capacity and logistics, fuel-specification requirements, and any carbon or clean-fuel program costs embedded in the pump price.

State policies that show up at the pump

PolicyDetail
Carbon program on motor fuelNo
State-specific fuel blendNo

State government control

Control todayUnified Republican (Governor + House + Senate, all R)
Years of unified Democratic control, 2001–20250
Years of unified Republican control23
Years of divided government2

Fuel-tax levels and fuel-specification programs are set by legislatures and governors; the national comparison shows average prices and taxes grouped by state control.

Compare: all states ranked · South Carolina electricity rates · gasoline prices by country

Sources: AAA (pump prices, updated daily; the industry-standard 50-state series), Tax Foundation (2026 state fuel taxes), EIA (WTI crude). The residual is computed, not reported. See methodology.