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Why Is Diesel More Expensive Than Gas? Taxes, Refining and the 2026 Squeeze

Diesel has cost more than regular gasoline almost every week since 2004, and the gap is unusually wide this fall. Here is what the EIA says goes into each gallon, why 2026 hit diesel harder, and what the Russian diesel deal does and does not change.

If you fill up a diesel pickup or work truck, you paid far more per gallon this week than drivers buying regular. On October 13, AAA’s national average was $6.2787 for diesel and $4.3413 for regular gasoline. Finding diesel more expensive than gas is nothing new, since the EIA says it has been that way almost continuously since 2004, but the reasons it costs so much extra in 2026 go well beyond the usual ones.

Where it stands: The Energy Information Administration’s weekly survey for October 5, published October 6, showed on-highway diesel at $6.199 and gasoline at $4.354, FleetOwner reported. Compared with a year earlier, diesel was up $2.488 a gallon and gas was up $1.230. The EIA posts its next weekly numbers on October 14.

Below is a plain-English look at what you pay for in each gallon, why diesel usually carries a premium, what changed this year, and what the Russian diesel deal can and cannot do about it.

The two fuels side by side

These are the figures as each source published them. We have not calculated the gap ourselves; compare the columns.

Measure (source) Diesel Regular gas
AAA average, Oct. 13 $6.2787 $4.3413
AAA average, a year earlier $3.6533 $3.0821
EIA survey, week of Oct. 5 $6.199 $4.354
EIA September average $6.29 $4.35
EIA forecast for 2027 about $4.50 just under $3.60

Two things stand out. Diesel sits above gas in every row, including the forecast. And the year-ago row shows the premium was far narrower before this year’s energy shock.

Why is diesel more expensive than gas? The EIA’s three reasons

According to the EIA, on-highway diesel has cost more than regular gasoline per gallon “almost continuously since September 2004.” The agency gives three reasons.

1. Global demand. Diesel and similar distillate fuels are in heavy demand worldwide, the EIA says, “especially in Europe, China, India, and the United States.” The International Energy Agency estimates that diesel and gasoil make up nearly 30% of global oil demand. That matters at home because, as the EIA puts it, international demand for distillate fuel affects what Americans pay for diesel.

2. Cleaner fuel costs more to make. The EIA notes that the U.S. move to ultra-low sulfur diesel raised the cost of both producing and distributing it.

3. A higher federal tax. Washington collects 24.40 cents on every gallon of highway diesel, the EIA says, a levy 6 cents a gallon steeper than its excise tax on gasoline. On top of that, state taxes and fees on diesel averaged 35.86 cents per gallon as of January 2026, and local and sales taxes can add more depending on where you buy.

What is inside a gallon of diesel

The EIA breaks the pump price into four parts: the refiner’s cost for crude oil, refining costs and profits, distribution and retail costs and profits, and taxes. Crude is the biggest slice. From 2004 through 2025 it made up about 51% of the average U.S. retail diesel price, the agency says.

Refining matters too. U.S. refineries get about 19 to 20 gallons of gasoline but only 11 to 13 gallons of ultra-low sulfur distillate out of one 42-gallon barrel of crude, the EIA says. Most of that distillate is sold as diesel, and some as heating oil. That smaller yield has consequences when diesel runs short. This fall the EIA described diesel markets so tight that refiners need extra crude just to meet diesel demand, which in turn puts upward pressure on crude prices.

Why diesel jumped more than gas in 2026

This year the usual premium ballooned. The EIA wrote in April that after the war with Iran began, “jet fuel and distillate prices have increased significantly more” than gasoline, because lost Middle East exports hurt those fuels far more. By September, the IEA said, U.S. diesel/gasoil prices had passed $200 a barrel, 94% above pre-war levels.

NBC News, using AAA data, reported on October 13 that the national diesel average had risen 70% since the Feb. 28 U.S.-Israeli strikes on Iran, while unleaded gas gained more than 45% over the same stretch. Same war, very different hit at the pump.

Diesel also touches everything you buy. The EIA says diesel engines in trucks, trains, boats and barges “help transport nearly all products people consume,” so the diesel price matters even to households that never fill up with it.

The seasonal angle: why fall and winter matter

Heating oil and diesel are, in the EIA’s words, “practically the same fuels.” That link explains the old pattern: before 2004, diesel was generally cheaper than gasoline except in cold winters, when heating oil demand pushed it higher.

The link still matters. “During the fall and winter, the demand for heating oil affects diesel fuel prices,” the EIA says, and in some regions seasonal swings in farm demand move prices too. By that account, the colder months ahead tend to add pressure on diesel rather than relieve it. Demand for diesel also tends to follow the economy, since it is a major transportation fuel.

What the Russian diesel deal changes, and what it does not

On October 9 President Trump said Russia would release diesel to world markets, and the Treasury Department said the same day it would ease sanctions on Russia through April 7 so the fuel could move, NBC News reported. Analysts expect little effect on what diesel costs. According to CNBC, Goldman Sachs figures the Russian cargoes due in October and November would shave only $1 to $2 from the wholesale price of a barrel of diesel along the Gulf Coast and in Europe. CNBC also calculated that the total amount Trump announced equals about 10 days of U.S. domestic demand.

None of the three standing reasons diesel costs more changes with the deal: the federal tax gap, the cost of ultra-low sulfur fuel and global demand all stay in place. The EIA still forecasts diesel at about $4.50 a gallon on average next year, above its gasoline forecast of just under $3.60.

If you drive a diesel and want to cut what you spend while prices stay high, see our guide on how to save money on diesel in 2026. If you are weighing a different vehicle altogether, our EV vs. gas cost comparison walks through the math for electric cars.

Frequently Asked Questions

Why is diesel more expensive than gas?

The EIA gives three long-running reasons: strong worldwide demand for diesel and other distillates, the extra cost of making and distributing ultra-low sulfur diesel, and a federal excise tax 6 cents per gallon higher than the tax on gasoline. In 2026 the Iran war added a fourth, because lost Middle East exports hit diesel far harder than gasoline.

How much is diesel compared with regular gas right now?

AAA put the national average at $6.2787 a gallon for diesel and $4.3413 for regular on October 13. The EIA weekly survey for October 5 showed $6.199 for diesel and $4.354 for gasoline.

Has diesel always cost more than gasoline?

No. The EIA says diesel was usually cheaper than regular gasoline before September 2004, except in cold winters when heating oil demand pushed it up. It has been higher almost continuously since then.

Does diesel get more expensive in winter?

It can. Heating oil and diesel are practically the same fuel, so the EIA says demand for heating oil in the fall and winter affects diesel prices.

Will Russian diesel make diesel cheaper than gas again?

Analysts do not expect it to change much. Goldman Sachs estimated the first Russian shipments would lower wholesale diesel by only $1 to $2 a barrel, according to CNBC, and the EIA forecasts diesel will still average about $4.50 a gallon in 2027, above its gasoline forecast.

Sources

This article is general consumer information, not financial advice. Fuel prices and policy are changing week to week; figures are as reported by the sources cited on the dates shown.

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