A gallon of diesel cost $6.32 on average across the country on Oct. 6, up from $3.68 a year earlier, AAA’s daily fuel report says. The exact figures were $6.3151 now and $3.6790 on the same date in 2025. That is $2.64 more per gallon, a jump of about 72 percent in twelve months.

The gap is large enough to show up on any receipt. A 20-gallon fill-up at today’s average costs about $53 more than it did a year ago.

For owners of diesel pickups and SUVs, and for anyone who buys diesel by the tank for a generator, tractor or camper, the practical question is how much more each fill-up costs and whether prices are coming down. The short answer from the past week is that prices are slipping, but slowly, and they are still far above where they stood a year ago.

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Diesel now costs far more than gasoline

The same AAA report puts regular gasoline at $4.3685 a gallon on Oct. 6, against $3.1333 a year ago. That is about $1.24 more than last October. Diesel rose twice as much.

The result is a wide gap between the two fuels. Diesel now sits about $1.95 above regular gasoline. A year ago the gap was about 55 cents, based on AAA’s year-ago figures of $3.6790 for diesel and $3.1333 for regular. Anyone who switched between a diesel and a gasoline vehicle, or who fills both kinds of tanks, will see that spread at the pump.

A month of price moves

AAA’s daily report lists earlier readings for comparison. Diesel averaged $5.8970 a month ago, so the national price has risen about 42 cents since early September. It was $6.4391 a week ago, which means it has fallen about 12 cents in the past seven days. Yesterday’s average was $6.3207, so the drop on Oct. 6 itself was a little over half a cent.

Gasoline has followed the same course. The national average for regular was $4.4558 a week ago and stood at $4.3685 on Oct. 6, so it has dipped about 9 cents while still sitting well above where it was a month ago, at $4.1473.

What the federal weekly count shows

The U.S. Energy Information Administration runs its own weekly survey of retail prices, so its numbers differ slightly from AAA’s. On Oct. 6 the EIA’s gasoline and diesel update put on-highway diesel at $6.199 a gallon, down 18.3 cents from the week before and up $2.488 from a year ago.

The two sources agree on the direction. Diesel is well above last year and has eased over the past week. EIA’s figure is about 12 cents lower than AAA’s because the two count prices differently.

California and Texas sit far apart

Where a driver lives matters a great deal. On AAA’s state-by-state price table, California’s diesel averaged $8.3641 a gallon on Oct. 6. Texas averaged $5.7358, among the lowest in the country, with Louisiana at $5.8410 and Mississippi at $5.8959.

That is a spread of about $2.63 a gallon between the two ends of the table. EIA’s survey shows the same pattern by region: West Coast diesel averaged $7.229 and California $8.082.

A driver in a high-price state faces a larger bill for the same trip. Someone filling a 20-gallon tank in California at AAA’s average would pay roughly $167. The same tank in Texas would cost about $115.

Why a daily average is only a guide

AAA’s national number blends prices from stations in every state, so no single station is likely to match it. The national figure shows the direction and size of a move. It does not predict the price at the pump down the road.

For that reason the most useful comparison is the local one. A driver who notes the price at the usual station once a week can see whether it is moving with the national trend, which has been down about 12 cents on the week, or running against it.

Following the next diesel update

AAA refreshes its national and state averages every day on its fuel prices site, and EIA posts a new weekly figure. Both are free and need no sign-in. Checking them side by side gives a sense of whether a price move is a one-day wobble or a lasting trend.

Before a long drive, it helps to look up the state average for each state along the route, since AAA’s table shows a gap of more than $2.60 a gallon between California and Texas. Keep a note of the last fill-up price and the gallons pumped, so the next one can be compared on both figures.

The central number stays the same for now. AAA’s report shows diesel at $6.3151 a gallon on Oct. 6, against $3.6790 on the same date last year.

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This article was produced with AI assistance and edited for accuracy against the sources linked above.