Why gas prices differ so much by state

The EIA publishes a weekly retail gasoline price for nine states. For the week of September 21, 2026, regular gasoline averaged $6.00 a gallon in California and $3.93 in Texas, against a U.S. average of $4.48. The gap between the two was $2.07 per gallon.

Because outages can move one state for weeks at a time, the table below averages each state’s weekly difference from the U.S. price over three multi-year periods. Positive numbers mean the state ran above the national average.

Every gallon carries the same federal tax of $0.184, so federal tax does not explain differences between states. State taxes do vary. In the EIA’s July 2026 (revised August 2026) table, total state taxes and fees range from $0.089 a gallon in Alaska to $0.736 in California, with a 51-jurisdiction average of $0.338. [7] Some states collect general sales tax on fuel on top of excise, which is why a state with a moderate excise rate can rank high on total tax. The full ranking is on the gas tax page.

Taxes are the easiest cause to measure, and they account for a minority of the largest gaps. California’s state taxes exceed Texas’s by 53.6¢ a gallon. Over 2020–2025, the average pump-price difference between the two states was $1.59. At current rates, tax covers roughly 34% of that difference. The remainder comes from the cost of producing and delivering the fuel and from retail margins.

The EIA groups the country into Petroleum Administration for Defense Districts, or PADDs, five regions first used to ration gasoline during World War II and still used to track how fuel moves between regions. [3] Refining capacity is concentrated in one of them: the Gulf Coast holds 55% of U.S. refining capacity. [4] The EIA notes that retail prices “tend to be higher the further gasoline must be transported to the point of sale.” [1]

The 2025 averages below show that pattern. The Gulf Coast was the cheapest region at $2.68, 42.0¢ below the U.S. average. California, which has no pipeline connection to Gulf Coast refineries, was the most expensive at $4.41. The Rocky Mountain region averaged −7.6¢ against the U.S. price.

Federal reformulated gasoline (RFG) burns more cleanly than conventional gasoline and is required in areas with high smog levels. It is sold in 17 states and the District of Columbia and makes up about 25% of U.S. gasoline. California runs its own statewide program, which the EPA and EIA both describe as more stringent than the federal one. [5] [1] In summer, federal rules cap gasoline volatility at 9.0 pounds per square inch (psi), and some areas, including Denver and Beaumont–Port Arthur, have a stricter 7.8 psi limit. [6]

Each extra specification narrows the set of refineries that can supply a market, which matters most when a nearby refinery goes down. The EIA reports a reformulated price for California, Massachusetts, New York, and Texas. It reports only conventional gasoline for Florida, Minnesota, Ohio, and Washington. Colorado has a reformulated series only from November 2023. That matches the date conventional gasoline sales became prohibited in the Denver area, November 7, 2023, after the EPA reclassified the area’s ozone status as severe. [8]

Two of the nine states put a carbon price on fuel. California brought gasoline and diesel suppliers under its cap-and-trade program on January 1, 2015. [9] The EIA’s tax table also notes that California fuel carries costs from the state’s Low Carbon Fuel Standard. [7] These costs are not taxes, so they do not appear in the tax column above. They reach the pump through wholesale prices.

Washington’s cap-and-invest program started on January 1, 2023, and fuel suppliers are among the covered entities. [10] In our data, Washington’s average premium over the U.S. price was 63¢ in 2022 and 94¢ in 2023. That is the largest one-year widening in the state’s weekly record, though the same year also included refinery and crude-cost changes, so the step cannot be assigned to the program alone.

Station-level costs and competition also differ. The EIA notes that prices “are often highest in locations with fewer gasoline stations,” and that rent, traffic, and supply sources vary even between neighboring stations. [1] [2] Statewide averages blur these effects, and the EIA survey does not break them out, so this site does not estimate their size.

Supply disruptions show up clearly in the weekly data. They hit hardest where a market depends on few refineries. Colorado has one refinery, in Commerce City, which shut down in late December 2022 after cold-weather damage. [11] In our data, Colorado went from 19¢ below the U.S. average in the week of January 9, 2023, to 72¢ above it in the week of February 20. That was Colorado’s widest premium on record. California’s widest weekly premium, $2.43 over the U.S. average, came in the week of October 3, 2022, during West Coast refinery outages. The reasons California runs high year-round are covered in why California’s gas is so expensive.