Diesel Spot to Pump: How Long Until Wholesale Moves Reach You

Why this matters. The wholesale price of diesel jumped this month and the pump sign has not changed yet. Do you fill up now or tomorrow? History says that is the wrong question. The pump follows wholesale with a delay, the delay is partial at first, and the size of the miss is bigger than most weekly moves. What you can do is read the lag and plan cash for it.

How much of a spot move reaches the pump

Take a 4-week change in the spot price. Then look at how much the U.S. retail price changed from the start of that window. A straight-line fit over 558 weeks gives these results:

Source: EIA open data, retrieved Oct 10, 2026, as fitted on our spot to pump page. Correlation falls as the horizon grows, so the link gets looser with time.

Read the first row this way: when spot rose 100 cents over 4 weeks, the pump had typically risen 63 cents by the end of those same weeks. Four weeks after that it was 82 cents, and 8 weeks after, 90 cents. Not 100. The rest goes to margin, taxes and the difference between one harbor and the whole country.

The gap between wholesale and the pump

The retail price minus the spot price was $1.328 a gallon in the latest week of the snapshot (week of Oct 5, 2026). Over the last 104 weeks the middle value was $1.336, and the range from the 10th to the 90th percentile was $1.173 to $1.492. So the gap itself is steady. What moves is the wholesale part under it.

Rough split from mixed locations and weeks, so refining and the last line absorb the differences. EIA publishes its own, more careful breakdown.

A worked example in gallons

Example data: your fleet buys 1,500 gallons a week. The latest 4-week change in the spot price in our snapshot was 26.7 cents a gallon. Using the 4-weeks-later slope of 0.82:

The gallons are invented and the fit ignores the small drift term, so treat it as the size of the question, not a prediction. It still shows why a surcharge keyed to the weekly pump price lags: it follows the pump, which follows spot.

The typical miss around such a fit is 13 to 38 cents a gallon depending on the horizon. That is larger than most weekly moves, which is why this page describes the lag and does not time purchases.

What to do with a lag

• Warn your cash plan. A big spot move means the pump is likely to follow over the next 4 to 8 weeks. Raise the fuel line in your forecast before the receipts show it.
• Do not chase the pump. A fuel card discount or a better stop beats trying to guess a week.
• Read your surcharge in this light. A schedule tied to a weekly retail price moves with the same delay. If you are checking one load, the fuel surcharge check shows both the pickup week and the week before.
• Date every figure. The weekly series is revised, and the snapshot above was retrieved on Oct 10, 2026.

Common questions

• What is the spot price here? The EIA weekly New York Harbor ultra-low-sulfur diesel spot price, the wholesale price in one harbor. Retail diesel is a national average of pump prices. They are related, but one harbor is not the whole country, so the link is loose.
• Can I use this to time my fuel stops? No. The fit describes the past, including the 2020 to 2022 shocks, and the typical miss is large next to a weekly move. Use it to see how quickly pump prices have followed wholesale prices.
• Why is the retail minus spot gap so large? It covers distribution, marketing margin and taxes, and it includes the difference between one wholesale harbor and the national retail average.
• How current is this? The snapshot was retrieved Oct 10, 2026. The latest retail week is Oct 5, 2026 and the latest spot week is Oct 2, 2026. EIA updates its weekly series on Mondays and Wednesdays, and the latest week can be revised.

Put your own gallons into the spot to pump calculator and see what a move can mean per week. If you suspect your fuel costs and surcharges are drifting apart, send us your last 20 loads and we will compare them.