Why Is California Gas So Expensive? 2026 Layers

California regular gasoline averaged $6.031 a gallon in the EIA’s weekly survey for October 19, 2026, against $4.284 for the United States, a premium of $1.75. About 70 cents of the usual premium can be traced to two California-only items, a state excise tax well above the national norm and the cost of two state carbon programs. The rest sits in a special gasoline blend, a refining sector that has lost two plants in a year, and retail margins that no agency measures cleanly.

The premium is not new, but 2026 changed what it is made of. When Brent went from $71 in February to $103 in March, crude cost became the largest single piece of the California price again, yet the gap over the national average widened by only about 20 cents, from $1.31 in 2025 to $1.51 from March to September. The Strait of Hormuz disruption behind that jump is described in the Hormuz flows guide, and the 51-row state tax table and a California versus Texas worked example are in why gas prices differ by state. The California Energy Commission’s own price stack, set against EIA national prices, shows which layers moved when crude rose by nearly half and which stayed put.

Where the price stands this month

California’s weekly price has climbed since early September. It peaked at $6.227 in the week of October 5 and eased to $6.031 two weeks later. The EIA’s weekly series starts in May 2000, and in that history only one week was higher: $6.271 for June 13, 2022. The October 5, 2026 reading was 4.4 cents below that record, and the week of June 20, 2022 ($6.216) was just below it.

The gap in Table 1 ranged from $1.51 to $1.87 in these seven weeks. Since January 2025 it has ranged from $1.10 to $1.87, and the $1.87 of the week of October 5 is the widest in that period, though not close to the widest of the series: the weeks of October 3 and 10, 2022 reached $2.43 and $2.24. Those 2022 weeks show the gap can run wider than it does now, and that it moves for reasons other than the crude price.

One gallon, nine layers

The CEC splits California’s monthly average price, which it takes from the EIA, into nine parts. The first three are market prices: what refiners reported paying for crude, the margin between crude and wholesale gasoline, and the margin between wholesale gasoline and the pump. The next two are the costs of California’s carbon programs. The last four are taxes and a fee. Table 2 sets the 2025 average beside August 2025, the month before the 2026 shock began to bite, and the two months that bracket the price jump.

The tax rows are about the same size in all four columns: 91 cents in the 2025 average and 96 cents in August 2026 on a price that rose from $4.44 to $5.46. The carbon-program rows together were 38 cents on the 2025 average and 49 cents in August 2026, up 11 cents. And the crude row and the refining row are the only items that rose by more than 15 cents between February and August, and together they account for 77 percent of the $1.12 rise.

What changed between February and August 2026

February 2026 is the last month before Brent crude jumped: it averaged $70.89 and then $103.13 in March, $117.29 in April and $91.08 in August (EIA, Europe Brent spot, series RBRTE). The EIA’s October 2026 Short-Term Energy Outlook attributes the surge to disruption of crude flows around the Strait of Hormuz, and estimates Middle East crude production shut-ins averaged 4.8 million barrels a day in September, down from a peak of 10.9 million in May. Those are the EIA’s estimates of what happened, and this page adds no forecast to them.

The California retail price rose $1.12 from February to August. Crude cost supplied $0.57 of it. The refining margin supplied $0.29, and the distribution margin $0.14. Carbon programs added $0.06, and the four taxes and fees together $0.05, most of that the July 1 excise increase from 61.2 to 63.4 cents and the sales tax applied to a higher price. The pattern is the usual one for a crude shock: the crude row moves first, the refining margin widens as product markets tighten, and the pump margin is squeezed and then recovers. The EIA made the same point about the national picture in its October outlook, writing that retail and distribution margins in 2026 have been depressed because of surging wholesale prices.

The refining row deserves a second look because it is where California-specific supply problems would show up. It was $0.505 in January 2026, $1.048 in August, and peaked at $1.238 in May. The 2025 monthly range was $0.458 to $1.054. So the August 2026 figure is at the top of the 2025 range, and May 2026 above it. That is consistent with a tight market, and it does not distinguish between a global product shortage and a California-specific one. The national comparison in the next section is the tool that can.

The test: did the premium grow when crude doubled?

If California’s premium were mostly a percentage markup, it would have roughly doubled when the crude price went from the low $60s to $100. It did not. Table 3 lists every month from January 2025, with the California and US retail averages, their difference, Brent and the wholesale spot premium for Los Angeles gasoline over Gulf Coast conventional gasoline.

In 2025 the average gap was $1.31; in January and February 2026 it was $1.31; and in March to September 2026, with Brent averaging $100 instead of $69, it was $1.51. The US price rose 43 percent between those two windows and California’s 34 percent. In dollars the gap grew by about 20 cents, and as a share of the US price it shrank, from 46 percent to 37 percent.

A straight-line fit across the 29 months from May 2024 to September 2026 says the same thing. Each extra dollar per barrel of Brent was associated with 3.3 cents on California’s monthly price, 2.7 cents on the US price, and 0.5 cents on the gap. A barrel holds 42 gallons, so a pure pass-through would be 2.4 cents; both prices ran a little above it because crack spreads widened with crude in 2026. The fit uses 29 points that include a single large shock, so it is a description of this period and not a law. Its message is narrow: a $50 swing in Brent moved California’s premium by roughly 27 cents, when the premium itself was $1.31 in 2025. Most of the premium is made of fixed cents per gallon, not of a multiple of the crude price.

The last column of Table 3 is the best single clue that something California-specific is also at work in wholesale markets. In 2025 the Los Angeles spot price averaged 30 cents above the Gulf Coast spot price. From March to September 2026 it averaged 36 cents, with a range of 19 to 53 cents, and the premium was 47 and 53 cents in March and April. The two prices are different grades at different places, so the premium measures the price of California’s blend and location together; it is not a cost-of-compliance estimate.

The layers only California has

A premium decomposition needs a reference point, and the EIA supplies one for taxes: in its May 2025 analysis of why California pays more, it gave the all-state average state gasoline excise tax as 28 cents a gallon, against California’s 60 cents at the time. The CEC supplies the carbon-program estimates. Table 4 puts the 2025 pieces together against the 2025 gap of $1.31.

Read the table as bounds. If California’s two carbon programs and its tax were all that separated it from the average state, the subtotal would equal the gap, and it covers 54 percent. The remainder of about 61 cents is where the special blend, the isolated refining system and station economics sit, and the wholesale memo line suggests about 30 cents of it shows up in the spot market. Anyone who tells you California’s premium is entirely taxes, or entirely refinery closures, is leaving out close to half of the gap.

One layer has moved since the table was built. The state excise tax reset on July 1, 2026, from $0.612 to $0.634 per gallon, according to the California Department of Tax and Fee Administration, which also lists a prepaid sales tax rate of 8.0 cents a gallon for gasoline from that date (7.5 cents the year before). The CEC’s own definitions page still says 61.2 cents “currently,” but its monthly data sheet carries $0.634 for July and August 2026, so this page uses the CDTFA figure. The step of 2.2 cents is small next to the crude swings in Table 2.

A refining system with less slack

California’s operable refining capacity was 1,499,171 barrels per calendar day on January 1, 2026, down from 1,748,171 five years earlier, according to the EIA capacity report covered in the refinery capacity guide. That count already excludes Phillips 66’s Los Angeles refinery, which ended operations in October 2025, and still included Valero’s Benicia refinery, which stopped refining in April 2026. The EIA removed Benicia from its monthly capacity estimates from March 2026. The two plants together were about 284,000 barrels a day of capacity, roughly 17 percent of the 1,637,871 barrels a day counted on January 1, 2025.

What replaces the lost output is mostly tanker cargo. Table 5 averages the EIA’s weekly West Coast (PADD 5) data for total gasoline imports and ending stocks. PADD 5 also includes Arizona, Nevada, Oregon, Washington, Alaska and Hawaii, so the series is wider than California, but California is the region’s dominant gasoline market.

Imports were already about 79 percent higher in January to September 2025 than in all of 2024, and peaked at 169 thousand barrels a day in the fourth quarter of 2025 as the Los Angeles refinery shut. They fell back after March 2026 even as prices rose; the weekly mean from May to October 16 was 92 thousand barrels a day. Stocks tell the other half of the story: West Coast gasoline inventories stood at 27.5 million barrels in the week of October 16, 2026, against 29.5 million a year earlier, 7 percent lower. The EIA has long noted that West Coast refineries hold lower inventory than the US average, which is why an outage shows up as a price spike before replacement cargoes can arrive.

Why not simply ship gasoline in from Texas? The EIA gives three reasons in its 2025 analysis. California is not connected by pipeline to the Rocky Mountains, only a few pipelines deliver from the Gulf Coast to the West Coast, and of the refineries with physical access to the state, only a few can produce California’s blend. Foreign refiners in India and South Korea do make the grade, but the EIA says shipping costs usually limit imports to outages and the summer driving season. The PADD guide explains why the EIA treats the West Coast as its own supply region, and the seasonal blend rules that compound this are in the summer versus winter gasoline guide.

Putting a price on each argument

The numbers above are enough to test the common explanations one at a time. They are not enough to rank them precisely, but they can say which ones the data supports.

Taxes explain a fifth of the pump price and a quarter of the gap

Taxes were 95.8 cents of the August 2026 price of $5.458. California’s state excise is the highest in the nation, but the federal part is the same everywhere, and California’s extra over the average state was 32 cents in 2025, or 25 percent of that year’s gap. The excise tax is 63.4 cents in total, so even removing all of it would not close a $1.31 gap.

Carbon programs explain about as much as the tax, and they are growing

The CEC’s carbon-program costs rose from 38 cents (2025 average) to 49 cents in August 2026. The Low Carbon Fuel Standard piece alone rose from 14.5 cents on the 2025 average to 22.9 cents, a 58 percent increase in a year that saw no change to the tax. The CEC labels both as pass-through costs, meaning what suppliers estimate they add to their wholesale price, and has not published a method that lets an outsider audit them.

Refinery closures are real, but the 2026 data cannot isolate them

The gap averaged $1.31 in January and February 2026, before Benicia closed and before crude spiked, and $1.51 afterwards. That is a 20 cents increase. An analysis that wants to credit it all to closures has to explain why the Los Angeles spot premium over the Gulf Coast was 47 cents in February, before the spike, and 39 cents in September, after both plants were gone. The same regional premium existed in April 2025 (43 cents) and September 2025 (43 cents), so wholesale California premiums of this size are not unique to the closure period.

Crude is not the reason California is expensive, but it is the reason this year is

The price of oil is set globally, and the gap in Table 3 barely responds to it. What oil did in 2026 was lift every state’s price by roughly the same number of dollars, and California’s was lifted from a higher base. A Californian paid $1.42 more per gallon, on average, in March to September 2026 than in January and February; a typical driver elsewhere paid $1.23 more.

Limits of this analysis

Several caveats shape what the tables can support. The CEC stack is built from monthly averages, so any single week, such as the October 5 peak, is not in it, and its latest month is August 2026 while the EIA weekly data runs to October 19. The CEC’s refinery and distribution lines are residuals, so measurement error in the wholesale price flows into both. The EIA gives the national average state excise tax as of March 2025, and no 2026 equivalent was found, so Table 4 is a 2025 accounting. The Brent and Los Angeles spot figures here are monthly means of daily data and do not capture intra-month spikes: Brent reached $131 a barrel on September 15, according to the October 2026 STEO, a month in which the monthly average was $114.16. Finally, the regression in the previous section includes only 29 months, one of which contains most of the variation in crude.

A short way to keep these figures honest when you meet them elsewhere: ask which month and which series. The EIA retail price, the AAA price and a regional station survey are separate surveys and can differ on the same day, and the CEC’s August 2026 figure of $5.458 is a month-long statewide average, not the price on a given day in a given city.

Data and sources: California Energy Commission, Estimated Gasoline Price Breakdown and Margins (spreadsheet dated October 15, 2026; definitions of terms; Low Carbon Fuel Standard and cap-and-trade estimates for January 2026), checked October 23, 2026. EIA, Weekly Retail Gasoline and Diesel Prices (California and US regular, through October 19, 2026) and Spot Prices (Brent RBRTE, WTI RWTC, Los Angeles RBOB, Gulf Coast conventional gasoline), monthly, checked October 23, 2026, from the EIA petroleum bulk data file updated October 22, 2026. EIA, Why California usually pays more at the pump for gasoline (May 5, 2025), checked October 23, 2026. EIA, Weekly West Coast (PADD 5) imports and stocks, through October 16, 2026, checked October 23, 2026. California Department of Tax and Fee Administration, Sales Tax Rates for Fuels (excise $0.634 from July 1, 2026, $0.612 for 2025-26), checked October 23, 2026. EIA, Short-Term Energy Outlook, October 6, 2026 (Brent monthly averages and September 15 daily high; shut-in estimates; margins comment), checked October 23, 2026. The refinery capacity figures are from the refinery capacity guide on this site, which cites the EIA Refinery Capacity Report. Differences, shares, averages and the regression are this page’s arithmetic; the Table 4 accounting is partial and labelled as such.