Prices sourced from EIA Weekly On-Highway Diesel Survey. Updated weekly. For informational purposes only - confirm at the pump before fueling. Full disclaimer
DIESELCOST

EIA Weekly On-Highway Diesel Survey - Updated July 20, 2026

US AVERAGE DIESEL COST PER GALLON 2026

$5.13/GAL

Survey week of July 20, 2026 (released Tuesdays), EIA Weekly On-Highway Diesel Survey

Cheapest State
$4.74
OK
Most Expensive
$6.95
HI
vs Gasoline
+$1.13
spread

Truck-Stop Chain Diesel Prices

Typical cash retail prices, week of July 20, 2026. Fleet-card discounts shown where publicly disclosed.

Pilot Flying J
$5.15
8-12c/gal (Pro Card)
~750 locations
Largest network. I-80 / I-40 corridor. Pro Card loyalty program.
Details ->
Love's Travel Stops
$5.12
8-10c/gal (Express Card)
~640 locations
Strong I-40 / I-30 corridor. Best grocery + quick-shop selection.
Details ->
TA Petro
$5.17
Up to 40c/gal (Comdata)
~280 locations
Best fleet-card discount with Comdata. Full-service trucking amenities.
Details ->
Independent / Regional
$5.24
Varies by chain
Roady's, AmBest, Bosselman, others
Often cheapest cash price. Limited national fleet-card acceptance.
Details ->

Prices are typical national retail estimates, not guarantees. Location-level prices vary. Sources: each chain's published fuel-price tool. Full comparison ->

Diesel Prices by State (2026)

Hover or click any state. State-level averages are AAA daily figures (July 28, 2026); the US average and PADD totals above are the weekly EIA reading from July 20, 2026. Full map + rankings ->

5 CHEAPEST STATES
Oklahoma$4.74
Kansas$4.83
Missouri$4.84
South Dakota$4.90
Kentucky$4.90
See all 50 states ->
5 PRICIEST STATES
Hawaii$6.95
California$6.89
Washington$6.13
Nevada$5.69
New York$5.60
See all 50 states ->

Quick Trip Calculator

Total fuel cost$366.43
71.4 gallons$0.733/mile
Full Trip Calculator (multi-leg + share) ->
FLEET DRIVER?

Fleet cards save $0.10-$0.40/gal at major chains. At 5,000 gal/month, that's $500-$2,000/month in savings.

Compare Fleet Fuel Cards ->

Why Diesel Costs $5.13/Gal Right Now

Diesel runs $1.13/gal above regular gasoline (which averages $4.00) in July 2026. The spread is more than double the historical average. Three immediate factors:

  • 1.
    Distillate inventories below the 5-year average. US distillate stocks have been running 10-15% below the 5-year average since late 2023. Tight supply pushes the NY Harbor crack spread above $1.40/gal.
  • 2.
    ULSD refining costs more than gasoline. Ultra-low sulfur diesel requires hydrotreating - a process that uses hydrogen to remove sulfur compounds. This adds $0.20-$0.35/gal of refining cost versus regular gasoline production.
  • 3.
    Heating oil and diesel are chemically identical. Both are middle distillates from the same refinery cut. Spring 2026 heating demand in northern Europe ran longer than seasonal models projected, competing with US diesel exports.
Full 5-reason explainer with crack-spread chart ->

US Diesel Price History (2021-2026)

$3.27
2021
$5.10
2022
$4.18
2023
$3.82
2024
$3.66
2025
$4.65
2026

2022 peak: $5.81/gal (Russia/Ukraine). 2026 spring spike: tight distillate supply. Source: EIA / FRED. Full history + EIA forecast ->

Frequently Asked Questions

What is the current price of diesel per gallon in the US?+
As of July 20, 2026, the US national average on-highway diesel price is $5.13 per gallon, according to the EIA Weekly On-Highway Diesel Fuel Survey. This is the retail price for ultra-low sulfur diesel (ULSD) at the pump, including all federal and state taxes. After bottoming at $4.58 on July 6, weekly prices rebounded through mid-July as renewed Strait of Hormuz tanker disruption, Russia's 8-31 July diesel export ban, and tight global refining margins lifted distillate prices.
Which state has the cheapest diesel fuel?+
Oklahoma has the cheapest diesel, averaging $4.74/gal as of July 28, 2026 (AAA), helped by proximity to Gulf Coast refining capacity - the largest refining complex in the US is in Texas and Louisiana - and a low 19-cent state diesel tax, well below the 74-cent Pennsylvania rate or the 102-cent California rate. Kansas ($4.83), Missouri ($4.84), Kentucky ($4.90), and South Dakota ($4.90) round out the five cheapest, all central states near major refining and freight corridors. Texas, despite hosting the largest US refinery complex, sits just outside the cheapest five at $4.98/gal.
Why is diesel more expensive than gasoline?+
Diesel runs $1.13/gal above gasoline as of July 2026. Five main reasons: (1) Ultra-low sulfur diesel (ULSD) refining requires hydrotreating that removes sulfur, adding cost and reducing yield; (2) Diesel and heating oil are chemically the same middle distillate - winter heating demand competes with truck fuel; (3) Federal diesel tax is 24.4 cents vs 18.4 cents for gasoline; (4) Freight demand is global and inelastic - trucks cannot switch fuels; (5) NY Harbor distillate crack spread averaged $1.42/gal in March 2026, well above the 5-year average. See the full explainer at /diesel-vs-gas.
How much does it cost to fill a semi-truck with diesel?+
A Class 8 semi-truck has 200-300 gallons of fuel tank capacity (typically two 100-150 gallon saddle tanks). At the $5.13/gal national average, a complete fill of 200 gallons costs $1,026; a 300-gallon fill costs $1,539. Most owner-operators fuel strategically, topping off when prices are favorable rather than running empty. A typical fueling stop is 100-150 gallons ($513-$770 at current prices).
Are truck-stop diesel prices different from gas station prices?+
At cash/retail prices, major truck-stop chains (Pilot Flying J, Love's, TA Petro) are often within a few cents of regular gas stations. The real savings come with fleet cards: Comdata saves up to 40 cents/gal at TA Petro, 10 cents at Pilot; WEX and EFS save 10-20 cents at major chains. Without a fleet card, the price at a truck stop is typically similar to or slightly higher than a nearby gas station. Pilot Flying J's FuelFinder app shows live local prices.
How much fuel does a semi-truck use per mile?+
Class 8 trucks average 6-8 mpg loaded on flat highways, 4-6 mpg loaded on hilly terrain or heavy loads, and 8-10 mpg empty. At 7 mpg and $5.13/gal, fuel cost per mile is 73 cents. For a 500-mile day: $366 in fuel. At 6 mpg (loaded, hilly): $428 for 500 miles. Use the fleet calculator at /fleet-fuel-calculator for your specific vehicle and route.
What is the best fleet fuel card for diesel discounts?+
For over-the-road truckers using multiple chains, Comdata typically offers the best discount - up to 40 cents/gal at TA Petro, 10 cents at Pilot, 8 cents at Love's. For owner-operators: EFS Fleet Card (WEX) saves 10-15 cents/gal. For chain-loyal drivers: Pilot Pro Card at Pilot locations, Love's Express Card at Love's. For mixed fleets: WEX Fleet Card offers the most granular spending controls. See the full comparison at /fleet-fuel-cards.
What will diesel prices do in 2026 and 2027?+
EIA's July 2026 Short-Term Energy Outlook (published July 8) projects retail diesel will average $4.61/gal for full-year 2026 and about $4.02/gal in 2027 as global refinery capacity grows and crude oil prices fall. That forecast predates a mid-July price surge: after bottoming at $4.58/gal on July 6, the weekly national average climbed to $4.80 on July 13 and $5.13 on July 20 - back above the STEO's full-year path - as renewed Strait of Hormuz tanker disruption, Russia's total diesel export ban (in force 8-31 July), and tight global refining margins pushed distillate prices up. The next STEO (due mid-August) will be the first to reflect these developments; treat the $4.61 full-year figure as EIA's early-July projection, not a current spot price.

How We Got These Numbers

National + PADD averages: EIA Weekly On-Highway Diesel Fuel Survey (PADD 1-5 + US composite). Published every Tuesday at 10am ET. Last verified: July 20, 2026. State-level breakdown: AAA Gas Prices daily state diesel averages, last refreshed July 28, 2026.

State-level prices: AAA Gas Prices state diesel averages, cross-referenced with EIA PADD-level regional data. State prices are representative daily averages; actual pump prices vary by location.

Truck-stop chain prices:Typical national retail estimates sourced from each chain's published fuel-price tool (pilotflyingj.com, loves.com, ta-petro.com). Confirm at the chain's app before fueling.

Disclaimer: DieselCostPerGallon.com is an independent informational resource. We are not a fuel retailer, truck-stop operator, fleet card issuer, or affiliated with any energy company. Always confirm current pricing at the pump or via your fleet card portal before refueling.