Gas prices by state FAQ - 12 questions
The dozen questions readers ask us most about US gasoline pricing. Each answer is short. Each answer carries a source. [EIA · 13 Jul 2026]
Why does AAA differ from EIA differ from GasBuddy?
Three different methods. EIA surveys 800 stations weekly. AAA aggregates daily OPIS feeds from 60,000+ stations. GasBuddy crowdsources from app users. EIA is slowest, GasBuddy fastest.
What is RBOB and why does it matter at the pump?
Reformulated Blendstock for Oxygenate Blending. The NYMEX RBOB futures contract is the wholesale gasoline benchmark; daily moves flow to the pump within 7-21 days.
Why are summer gas prices higher than winter?
Summer-spec gasoline (lower Reid Vapor Pressure, less butane) costs more to make. Driving demand peaks at the same time. Inventory draws push spot prices up. The switchover starts each March 1.
Why is California gas so expensive?
CARB summer blend specification, the highest US state excise (63.4 c/gal), cap-and-trade and LCFS fees, sales tax on fuel, and isolated PADD 5 refining all stack.
How much is the federal gas tax and where does the money go?
18.4 cents per gallon gasoline, 24.4 cents per gallon diesel. Unchanged since October 1993. Revenue flows to the Highway Trust Fund (84 percent highways, 16 percent transit).
When does EIA release weekly retail prices?
Every Monday around 5 p.m. ET, except federal holidays (Tuesday). Survey reflects Monday morning prices.
Why is diesel sometimes higher than premium gasoline?
Year-round trucking demand, ULSD specification cost, and winter heating-oil correlation in the Northeast keep diesel structurally above regular and often above premium.
What is the cheapest day of the week to buy gas?
Empirically Monday or Tuesday in most markets; Thursday is typically the most expensive. The pattern is small (3-5 cents) and not reliable for every station.
How much does a hurricane move prices?
A major Gulf landfall typically adds 5-15 cents to the national average for 2-4 weeks. Refinery shut-ins drive the spike; pump returns when units restart.
What is Tier 3 gasoline?
EPA Tier 3 sets sulfur, benzene and aromatic limits on gasoline sold nationwide since 2017. It adds about 1 cent per gallon over Tier 2.
Is regular OK in a car that says 'premium recommended'?
Usually yes - modern knock sensors retard timing to handle 87 octane. 'Premium required' is different. Performance may decline slightly.
Are gas prices going to keep falling in 2026?
EIA STEO and GasBuddy both project a soft year, around 3.87/gal national average for 2026 - the fourth annual decline. Hurricane season and OPEC+ remain swing risks.
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