Gas Prices Are Up 34% In A Year. Here’s How Much More Americans Are Spending To Fill Up.

American drivers are paying nearly $19 more to fill a 15-gallon gas tank than they were a year ago, as rising fuel prices add to household expenses and push inflation higher.

The national average price of regular gasoline stood at $4.33 a gallon on Wednesday, compared with $3.08 a year earlier, according to AAA's daily fuel price data. That puts the cost of a 15-gallon fill-up at approximately $65, up from $46 last October.

The increase comes as gasoline prices surged 34.2% in the 12 months through September, according to the Bureau of Labor Statistics' Consumer Price Index report released Wednesday.

Gasoline prices rose 9.1% in September alone, accounting for more than half of the 0.6% monthly increase in overall consumer inflation. Annual inflation accelerated to 3.7%, from 3.4% in August, while the broader energy index increased 20.4% over the year.

AAA's latest pump-price figures show an even larger year-over-year increase of approximately 40.9%. The difference reflects the fact that AAA tracks daily retail gasoline prices, while the BLS measures monthly changes in consumer prices using a separate methodology.

For drivers purchasing 40 gallons of gasoline a month, the difference between AAA's current and year-earlier prices amounts to approximately $50 in additional monthly spending.

That works out to roughly $603 over a year if prices and fuel consumption remain at those levels. A motorist purchasing 60 gallons monthly would spend approximately $75 more each month, or about $905 annually under the same assumptions.

The figures are illustrative calculations based on AAA's national averages, rather than estimates of what every American household spends. Actual expenses vary according to driving distances, vehicle fuel efficiency and local gasoline prices.

The latest increase follows considerable volatility in gasoline markets throughout 2026. Data from the U.S. Energy Information Administration show that regular gasoline prices climbed sharply during the spring before easing over the summer and rising again toward September.

Fuel prices have been affected by disruptions to global energy supplies amid the conflict involving Iran and restrictions on oil shipments through the Middle East.

The increase has been even steeper for diesel, a fuel widely used in commercial trucking, agriculture and freight transportation.

AAA reported a national diesel average of $6.30 a gallon Wednesday, compared with $3.66 a year earlier. That represents an increase of approximately 72%.

A commercial vehicle purchasing 100 gallons of diesel would therefore face a fuel bill roughly $264 higher than a year earlier at the national average prices.

The September inflation report also showed substantial increases in other energy costs. Fuel oil prices rose 15.3% during the month and 74.2% over the year, while electricity prices increased 4.4% annually and utility gas service costs rose 5%.

Core inflation, which excludes food and energy, increased 0.3% in September and 2.6% over the preceding 12 months. Gasoline prices also vary widely across the country, reflecting differences in state taxes, transportation costs, refining capacity and regional fuel supplies.

AAA's daily figures show that the national average remained below its June 2022 record of $5.02 a gallon, although motorists were paying substantially more than at the same time last year.