Why Is Diesel More Expensive Than Gasoline? The 2026 Gap, Explained

Diesel vs. gas prices: how big is the gap?

EIA surveys retail fuel prices every Monday. For the week of Oct. 19, 2026, on-highway diesel averaged $6.276 a gallon and regular gasoline $4.284. That's $1.99, or 46%, more for diesel. A year earlier the gap was $0.60 ($3.620 vs. $3.019). It has more than tripled.

EIA weekly retail prices, all taxes included. Record is the widest weekly gap in EIA's series, which starts in 1994 for diesel. FuelGo calculation.

These are pump prices. A bulk delivery is priced differently, off the terminal rack plus freight, taxes and margin, but it moves with the same market. For this week's retail, wholesale and inventory numbers, see the diesel price report.

Diesel vs. gasoline prices since 1995

Diesel hasn't always cost more. EIA says diesel was often cheaper than regular gasoline before 2004, except in some cold winters when heating demand pushed it up, and has been generally higher since September 2004. We averaged every week of EIA data by year to see how the gap moved:

FuelGo analysis of EIA weekly U.S. retail prices. Averages of weekly prices; 2026 runs through the week of Oct. 19.

• Before 2005, it was a coin toss. Diesel averaged less than regular gasoline in 7 of the 10 years from 1995 to 2004. In 2003 it was cheaper in 37 of 52 weeks.
• Since 2008, diesel has almost always cost more. Diesel was cheaper in 11 weeks of 2009 and 7 of 2015, and in no week of any other year since 2008. The last one was Aug. 24, 2015.
• The gap jumped in 2022 and again in 2026. It averaged $1.04 in 2022 and $1.24 so far in 2026, against 45¢ in 2019 and 56¢ in 2025.

Where the extra dollar goes: EIA's price breakdown

EIA splits each retail gallon into crude oil, refining, distribution and marketing, and taxes. Its latest split is for May 2026, when diesel averaged $5.60 and regular gasoline $4.48. We turned EIA's percentages into cents to see which pieces make up the $1.12 difference:

Shares from EIA, "What we pay for in a gallon of," May 2026. Cents are FuelGo's conversion of rounded shares, so rows don't add exactly.

The crude oil in a gallon of diesel and in a gallon of gasoline cost about the same, roughly $2.33–$2.35. Both come from the same barrel. Almost all of the gap sits after the crude: in refining costs and profits, and in getting the fuel from the terminal through the pump. Taxes add only a few cents. That's also why the common argument that diesel needs less refining doesn't make it cheaper. The refining slice moves with the crack spread, the market's price for diesel over crude, not with what it costs to run the unit. See how bulk diesel is priced for the same layers on a delivered load.

Why diesel costs more than gasoline: six reasons

1. Refiners are paid far more for diesel than for gasoline

The crack spread is the wholesale fuel price minus the crude price; EIA uses it as a gauge of refining margins. When diesel is scarce, its crack spread rises and pulls the retail price with it. Since March 2026, EIA said in early September, the New York Harbor distillate crack spread has averaged 74 cents a gallon more than the gasoline crack spread. EIA's reason: the disrupted refineries in Russia and the Middle East had supplied relatively more diesel and jet fuel to world markets than gasoline. U.S. refiners have shifted output toward distillate and jet fuel to capture those margins (EIA).

2. The world wants the same barrel

Diesel moves freight, runs farm and construction equipment, and powers standby generators. EIA points to strong demand for distillates in Europe, China, India and the U.S. A refinery can only push its yield so far: in 2023, U.S. refineries made about 19.6 gallons of gasoline and 12.5 gallons of distillate from each 42-gallon barrel (EIA). When overseas buyers bid up diesel, U.S. barrels go abroad. EIA says U.S. distillate net exports have stayed near or above their five-year range since February 2026, drawing down stocks at home. More on the barrel in how diesel is made from crude oil.

3. Winter heating competes for it, and the gap follows the seasons

Heating oil and diesel are practically the same fuel and are made at the same time, so heating demand in fall and winter puts pressure on diesel prices (EIA). Gasoline does the opposite: demand usually rises in summer. We checked the weekly data for 2010–2025, leaving out 2022's outlier year. The gap averaged 54¢ in December and 54¢ in January, but only 24¢ in June and 25¢ in May. Winter fuel adds cost too: blends cut with #1 diesel cost more and carry a little less energy per gallon (see #1 vs. #2 diesel).

4. Inventories are thin

Low stocks leave little cushion when a refinery trips or a cargo is late, and they raise refining margins. In the week ending Oct. 16, 2026, U.S. distillate inventories were 104.3 million barrels, about 9% below the five-year average for the time of year; gasoline stocks were 5% below (EIA). In September, East Coast distillate stocks were 32% below normal, EIA says. The weekly diesel price report tracks these numbers.

5. Ultra-low sulfur diesel costs more to make and move

Starting June 1, 2006, EPA required refiners to cut sulfur in highway diesel by 97%, from 500 to 15 parts per million, with all highway diesel at 15 ppm by 2010. EIA says the move to lower-sulfur diesel changed both production and distribution costs, and lists it with rising global demand as a reason diesel has cost more since the mid-2000s.

6. Diesel is taxed more, but only a little

Federal tax on highway diesel is 24.4 cents a gallon against 18.4 cents for gasoline, and the gap has been there since at least 1995 (FHWA). As of January 2026, state taxes and fees averaged 35.86 cents on diesel and 33.55 cents on gasoline (EIA). Together that's about 8 cents more on diesel: real money on a fleet's fuel bill, but about 4% of this month's gap. FHWA has said some states set higher diesel rates mainly because diesel vehicles get more miles per gallon. Including federal tax, highway diesel taxes run from $0.4483 a gallon in Oklahoma to $1.0003 in Pennsylvania (our diesel taxes by state table, as of October 16, 2026).

Why the diesel-gas gap hit a record in 2026

Everything above was already in place in January, when the gap was about 68¢. Then the supply shock hit diesel harder than gasoline. EIA's October outlook describes "extreme tightness in diesel markets."

Prices: EIA weekly retail. Events: EIA Today in Energy (Apr. 7, 2026), EIA STEO (July and Oct. 2026), Reuters via Al-Monitor (Sept. 1, 2026), AP (Oct. 9, 2026).

• Hormuz. After the Feb. 28 strikes, most shipping stopped moving through the Strait of Hormuz (EIA). A June 18 U.S.–Iran memorandum to end the conflict and open the strait brought more traffic (EIA), and diesel fell through early July. Fighting resumed around Sept. 1, and Iran effectively closed the strait to shipping again (Reuters). EIA's October outlook still assumes Middle East flows stay constrained through the fourth quarter.
• Refinery losses hit diesel hardest. Refining in Russia, China and the Middle East has been reduced, and the plants lost in Russia and the Middle East make relatively large shares of distillate (EIA). Russia has banned diesel exports since July, and the IEA says its diesel output is down about 30% (AP).
• Russian diesel is promised, not delivered. On Oct. 9 the White House announced a deal for Russian diesel, and Treasury issued a license easing sanctions on it until April 2027. The White House didn't say when the fuel would arrive (AP).
• The record. Retail diesel hit $6.529 in the week of Sept. 21, the highest nominal price in EIA's series since 1994, and the gap over gasoline reached $2.05.

Is diesel worth the higher price? Energy, mileage and cost per mile

Diesel buys more per gallon. The Alternative Fuels Data Center lists ultra-low sulfur diesel at 128,488 Btu per gallon (lower heating value) against 112,114–116,090 for gasoline blends, and rates a gallon of diesel at 1.12 gasoline gallon equivalents. Diesel engines also turn that energy into more miles: fueleconomy.gov says diesel vehicles often go 20–35% farther on a gallon than gasoline versions.

Even per unit of energy, diesel costs more right now: $6.276 ÷ 1.12 is about $5.60 per gasoline-gallon equivalent, 31% above regular. The mileage edge used to cover the price premium. In 2026 it doesn't:

FuelGo calculation: (diesel price ÷ gasoline price) ÷ (1 + mileage advantage) − 1. EIA retail prices; mileage range from fueleconomy.gov. Fuel only; ignores vehicle price, maintenance and resale.

To break even per mile at October's prices, a diesel would need to go about 46% farther per gallon than the gasoline version. That matters for light and medium-duty fleet buys where both engines are offered. For heavy trucks, generators and most construction equipment, there's no gasoline version to switch to, so the question is how to buy diesel well. To compare your own numbers, use the fleet fueling cost calculator.

What commercial diesel buyers can do about the price

You can't change the crack spread. You can control how you buy, what you put in which tank, and how much you burn doing nothing.

1. Buy delivered bulk instead of at the pump. A station price includes the retail station's costs and margin. A bulk price is built from the terminal rack plus freight, taxes and the supplier's differential, so you can see each layer and check it. See how bulk diesel is priced.
2. Use dyed diesel where it's allowed. Off-road equipment, generators and other nontaxable uses can run dyed diesel, which skips most fuel tax: $0.24 to $0.94 a gallon less depending on the state (as of October 16, 2026). Never in road vehicles. See dyed vs. clear diesel.
3. Claim back tax you shouldn't have paid. If clear, taxed diesel went into off-road equipment, you may be able to claim the federal tax back. See off-road diesel tax refunds.
4. Decide how much price risk you want. A fixed-price contract trades daily swings for a set price on set gallons. It protects a budget when prices rise and costs you when they fall. See fixed-price diesel contracts.
5. Cut idling. DOE says a heavy-duty truck burns about 0.8 gallon an hour idling, and a typical long-haul truck uses about 1,500 gallons a year that way. At $6.276, that's roughly $9,400 a truck per year.
6. Don't run tanks to empty when stocks are thin. Order with headroom. A tight terminal or a cold snap shouldn't turn into downtime or an emergency call.

Diesel delivery from FuelGo

FuelGo delivers clear on-road diesel, dyed off-road diesel for off-road equipment, gasoline, DEF and R99 renewable diesel nationwide. We quote OPIS-based or indexed pricing that moves with the market, with volume-tier pricing, and we offer fixed-price diesel contracts priced off NYMEX NY Harbor ULSD futures. Drops run from 20 to 4,400 gallons, with transport loads up to 7,500 gallons; we also wet-hose fleets through mobile fleet fueling and keep generators topped off.

FuelGo serves more than 5,400 commercial clients nationwide. Pay by credit card, ACH or check. Dispatch runs 24/7/365. Get a delivered quote or call 800-720-4546; a dispatcher replies within the hour.

Diesel vs. gasoline price FAQ

Sources: U.S. EIA, Gasoline and Diesel Fuel Update (weekly retail prices, week of Oct. 19, 2026; "What we pay for in a gallon of," May 2026) · EIA weekly U.S. on-highway diesel prices, 1994–2026 · EIA weekly U.S. regular gasoline prices, 1990–2026 · EIA weekly California diesel prices · EIA weekly California regular gasoline prices · EIA FAQ, why are diesel fuel prices higher than gasoline prices? · EIA, diesel prices and outlook (taxes, history) · EIA, factors affecting diesel prices · EIA, factors affecting gasoline prices · EIA, refinery inputs and outputs (2023 barrel) · EIA Today in Energy, crude oil and product prices rose sharply in 1Q26 (Apr. 7, 2026) · EIA Today in Energy, elevated crack spreads and crude prices (Sept. 4, 2026) · EIA, what goes into diesel prices? (Sept. 18, 2026) · EIA Short-Term Energy Outlook, July 2026 · EIA Short-Term Energy Outlook, Oct. 6, 2026 · EIA Weekly Petroleum Status Report, week ending Oct. 16, 2026 · Reuters via Al-Monitor, US launches new strikes on Iran (Sept. 1, 2026) · AP via PBS NewsHour, Russian diesel deal (Oct. 9, 2026) · EPA, June 1, 2006 clean diesel milestone · EPA, diesel fuel standards (ULSD phase-in 2006–2010) · FHWA, Highway Statistics 1995: motor fuel taxes · DOE Alternative Fuels Data Center, fuel properties comparison · fueleconomy.gov, diesel vehicles · DOE, idling reduction for heavy-duty vehicles (2015) · California Air Resources Board, diesel fuel program · Tax figures: FuelGo diesel taxes by state (standard rates, as of October 16, 2026; includes the small federal Superfund tax)