Will Gas and Diesel Prices Go Down After the Midterms?

In the week of Feb. 23, the last before U.S. and Israeli strikes on Iran, a gallon of diesel averaged $3.81 at American pumps, EIA data show. On Nov. 2, the latest weekly reading, the same gallon averaged $6.29.

That gallon has been in the price of nearly everything since. In its October Beige Book, the Federal Reserve reported that “Higher oil prices permeated all District reports. Firms reported elevated diesel prices and noted that fuel surcharges were passing on increased costs throughout the supply chain.”¹

On Jan. 3 a new Congress arrives promising to scrutinize the war that drove those prices. That may matter for crude. It has less reach over diesel's premium, which has been driven by refining, trade and supply problems that a vote in Washington does not fix quickly. Nearly half the oil executives surveyed by the Dallas Fed in September expect diesel's spread over crude to stay wide for more than a year. That makes diesel a contract question first.

Two fuels, two measures

Gasoline has risen too, from $2.94 a gallon in the week before the war to $4.15 on Nov. 2, an increase of 41%. Diesel's climb, 65%, is the steeper one, and it is the one that runs through a factory's costs, in every truck that delivers a coil or hauls away a pallet. Before the war, diesel cost 87 cents a gallon more than gasoline at the pump. On Nov. 2 that premium was $2.14.

That pump-to-pump premium is one measure. The one the oil industry watches is diesel's spread over crude, the gross gap between the two prices before refining and other costs, not a refiner's profit. Both have widened, and for overlapping reasons: refining capacity, inventories, export flows and the kinds of crude that make diesel best. Much of the world's diesel-friendly crude comes from the Persian Gulf, The New York Times reported. An oilfield services executive told the Dallas Fed in September: “I don't think Russian diesel exports will resume anytime soon, and China may hold the refining cards and ability to supply.”²

2006: one precedent, not a forecast

The last time voters handed both chambers to the opposition during a war was 2006. The Congress that took office in January 2007 passed the Energy Independence and Security Act that December, raising fuel economy standards and expanding the renewable fuel mandate, laws built for the next decade rather than the next year. Over the two years after the election, the producer price index for industrial chemicals rose 29% and steel mill products 24%. Prices broke when demand collapsed in the financial crisis, and manufacturing output fell 5.6% over the same 24 months.

An oil producer told the Dallas Fed in September: “A global recession could ease the pressure on prices for crude and refined products.” A recession is one way fuel gets cheaper. A ceasefire, the return of export flows and new refining capacity are others, and Congress's influence over any of them is indirect.

2026: the war, the reserve and the vote

This war began at the end of February. Brent crude peaked at $138.21 a barrel on April 7, the highest since our archive begins in 2021, and was $123.10 on Oct. 27. The weekly diesel average's high, in an archive that begins in September 2023, is $6.53, set Sept. 21. The government has leaned on its emergency stockpile: the Strategic Petroleum Reserve held 282.6 million barrels on Oct. 23.

The new majority's main energy lever is the war itself. Democrats plan a resolution requiring the president to end it or seek authorization from Congress. Earlier Senate attempts failed, the latest by 49 to 50. On Wednesday oil fell about 2% on the expectation of closer scrutiny, with WTI futures near $94, CNBC reported.

What the sellers expect

The case for quick relief deserves its hearing: end the war, reopen the Strait of Hormuz, and crude could fall fast. Diesel's spread over crude may be slower. In the Dallas Fed's September survey, 48% of oil executives said that spread would take more than four quarters to return to its 2025 level, against 36% who said the same of gasoline's.³ Their most common answer for when crude exports from the Persian Gulf return to normal was the second quarter of 2027.⁴

That is an expectation about the spread, not a forecast of the pump price.

That is an expectation about the spread, not a forecast of the pump price. If crude falls, diesel can fall with it even while its spread stays wide. Another executive in the same survey put the stakes in two sentences: “Diesel is the mother’s milk of the economy. We are just starting to see the impact on the wider economy.”

Five prices to test a contract against

For a buyer of freight, or a seller with a fuel surcharge, the practical answer is a set of cases rather than a forecast. These are illustrations built from the EIA's own numbers, not predictions:

Four features to check against all five cases: a reset on a fixed schedule, weekly or monthly; a named public index, such as the EIA's weekly on-highway diesel average; a stated base price; and movement down as well as up.

The freight cost per unit calculator turns a diesel price, a surcharge formula and a lane into a cost per unit shipped, so each of the five cases becomes a number. Run a fuel case through a freight rate

What Congress can and cannot do

Promises about fuel prices, from either party, meet the same constraint: Congress's levers over the price of oil are limited and slow, and the most direct one, over the war, is contested. When the new leaders say what they will do about fuel, the useful question is what it would do to a gallon, in cents, and by when. We will print their answers next to the EIA's weekly number.

Next Monday the EIA will publish another national average, as it does every week, and the gallon will have a new price. Neither the old Congress nor the new one will have set it.

Further reading

• Gasoline and Diesel Fuel Update, U.S. Energy Information Administration, the weekly source.
• Dallas Fed Energy Survey, third quarter 2026, Federal Reserve Bank of Dallas, Sept. 30, 2026.
• Tariffs to Iran war: can Democrats reverse Trump policy with midterms win?, Al Jazeera, Nov. 4, 2026.
• Stock market today, CNBC, Nov. 4, 2026, on oil's move after the election.
• On-highway diesel, regular gasoline and Brent crude, the live series behind this story.