# US diesel, explained How the numbers on this site actually work: the Monday DOE number, regional spreads, the pump-over-spot margin, cost per mile. Each guide is built on the same live data as the trackers, so the examples are real and current. ## The DOE number and the surcharge - [What is the DOE diesel price?](https://mondaydiesel.com/guides/what-is-the-doe-diesel-price.md) — The DOE diesel price is the US average retail price of on-highway diesel that the Energy Information Administration surveys every week and posts as the price for Monday. It is the number almost every fuel surcharge in US trucking is written against, which is why the whole trade watches for it. - [How fuel surcharges work](https://mondaydiesel.com/guides/how-fuel-surcharges-work.md) — A fuel surcharge passes fuel-price risk from the carrier to the shipper. A schedule sets a base fuel price, then adds a set amount per mile for every increment the DOE diesel number sits above that base, at a stated miles-per-gallon figure. - [Cost per mile: fuel math for an owner-operator](https://mondaydiesel.com/guides/diesel-cost-per-mile.md) — Fuel cost per mile is the diesel price per gallon divided by the truck's miles per gallon. At the DOE number for the week of Jul 6, 2026, $4.578 a gallon, a truck getting 6.5 mpg spends about 70.4 cents a mile on fuel. - [What fuel does and doesn't tell you about freight](https://mondaydiesel.com/guides/what-diesel-prices-tell-you-about-freight.md) — The diesel price is a cost, not a signal about the freight market. It tells you what a mile of fuel costs and it feeds the surcharge, but it says almost nothing about how many loads are moving or what they pay. Cheap fuel and a weak freight market sit together all the time. ## The price map - [What are PADDs?](https://mondaydiesel.com/guides/what-are-padds.md) — A PADD is a Petroleum Administration for Defense District, one of five regions the federal government groups the states into for petroleum data. EIA reports diesel prices by these districts, so reading a regional diesel number starts with the map. - [Why the West Coast pays more](https://mondaydiesel.com/guides/why-the-west-coast-pays-more.md) — The West Coast pays the highest diesel prices in the country, and California the most of all. Three things drive it: a stricter state fuel spec, higher state taxes and fees, and a refining map that leaves the region supplying most of its own fuel. ## Prices and how they move - [Retail, rack and spot: the diesel price ladder](https://mondaydiesel.com/guides/retail-rack-and-spot.md) — There is no single diesel price. A gallon carries a different number at each step from refinery to truck: a spot price at the trading hub, a rack price at the terminal, and the taxed retail price at the pump. Each sits above the last. - [Why diesel costs more than gasoline](https://mondaydiesel.com/guides/why-diesel-costs-more-than-gasoline.md) — Diesel usually costs more than gasoline for four structural reasons: higher taxes, costlier refining to hit ultra-low sulfur, export demand and competition for the same middle-distillate barrel from heating oil and jet fuel. - [Winter diesel: blends, gelling and the seasonal premium](https://mondaydiesel.com/guides/winter-diesel-blends-and-gelling.md) — Winter diesel is regular diesel treated or blended so it keeps flowing in the cold. Below a certain temperature the wax in diesel crystallizes, and if enough forms the fuel gels and stops passing through the filter, which is why northern diesel changes with the season and costs a little more. The basic, standard and premium labels at the pump are the seller's marketing, not grades in the fuel standard. ## Taxes and compliance - [What is IFTA?](https://mondaydiesel.com/guides/what-is-ifta.md) — IFTA, the International Fuel Tax Agreement, sorts out fuel taxes for trucks that cross state lines. Instead of filing in every state, you file one quarterly return with your base state, and it settles the tax to each jurisdiction based on where you actually burned the fuel. --- Canonical URL: https://mondaydiesel.com/guides