EIA Diesel Prices and Fuel Surcharges: Build a Quote You Can Reproduce

What the EIA benchmark represents

EIA’s on-highway diesel series estimates retail cash self-service prices including taxes. Its methodology describes a sample of outlets across the contiguous United States and weighted national, regional, and California estimates. It is a statistical benchmark, not a receipt from the carrier’s fuel purchase and not a quoted wholesale rack price.

Sources: EIA weekly diesel-price methodology

Monday observation does not mean Monday publication

At the September 28, 2026 source check, EIA’s current methodology says it collects prices as of 8 a.m. local time Monday and publishes average estimates around 10 a.m. Eastern on Tuesday. Government holidays can move publication to Wednesday while the observations still represent Monday’s prices. Use the current release calendar rather than repeating an older Monday-publication rule.

That timing can affect a Monday quote or a contract with a delayed reference week. Save the observation date and identify the applicable release. A freshly retrieved prior-week value remains a prior-week value. If the current release is not yet available, label the value used and follow the agreement’s fallback rather than presenting an estimate as a published number.

Sources: EIA weekly diesel-price methodology

Work through a per-mile example

For an illustrative agreement, suppose the surcharge equals the diesel benchmark minus a base fuel price, divided by an agreed fuel-economy factor. Assume a benchmark of $4.10 per gallon, a base of $1.50 per gallon, and 6.5 miles per gallon. The difference is $2.60 per gallon; dividing by 6.5 miles per gallon gives $0.40 per mile. Across 800 chargeable miles, the result is $320.

Those are invented numbers for demonstrating arithmetic, not current prices or recommended contract terms. The agreement must specify the reference series, timing, base, fuel-economy factor, mileage basis, rounding, and any floor or cap. If the formula produces a negative amount, do not silently replace it with zero unless the agreement calls for that treatment.

A percentage schedule is a different calculation

Some published carrier schedules express a fuel surcharge as a percentage. An illustrative 25% rate applied to a $1,200 eligible transportation charge gives $300. Applying 25% to a different charge base changes the answer even though the percentage is identical. Establish which charges the schedule covers and its effective period.

Do not interchange a parcel schedule, an LTL schedule, and a negotiated truckload formula simply because each contains the words “fuel surcharge.” Follow the named carrier’s official schedule and the applicable agreement. Where a schedule references an index with a lag, preserve that relationship; the latest available diesel price may not be the value used by the currently effective percentage.

Region and units belong beside the number

A national benchmark and a regional benchmark are not interchangeable defaults. Use the geography specified in the agreement. Similarly, dollars per gallon, cents per gallon, dollars per mile, and percent are distinct units. A copied number without a unit makes a calculation hard to review and can cause an error by a factor of one hundred.

In a saved quote, write the full input: series or region, USD per gallon, observation date, and value. Record whether miles are loaded miles, agreed route miles, or another contractual basis. Recalculating a quote later should use its saved inputs rather than silently replacing them with today’s benchmark or a revised route.

Handle stale and missing data explicitly

If a provider cannot retrieve the source, the interface should distinguish an unavailable current value from a previously obtained observation. An HTTP success or a recent “checked” timestamp does not make old data current. Keep the last observation date visible and prevent a missing value from becoming a zero surcharge by accident.

For a time-sensitive quote, document the fallback agreed with the customer: defer final pricing, use a specified earlier release, or apply another explicit contractual method. Do not invent a market price to keep the form moving. The recovery action should be clear to the broker who owns the quote.

Save the explanation with the quote

Keep the source link, series, observation and publication dates, effective schedule, formula inputs, mileage, eligible charge base, rounding, and final amount. State any exception or customer-approved substitution. This gives operations and billing the same calculation and makes a dispute about the charge easier to locate.