Service route fuel costs have moved sharply in twelve months, while many trip charges have not been revisited in years. The U.S. Energy Information Administration put the national average on-highway diesel price at $6.179 a gallon for the week ending October 12, 2026, which it reports as $2.514 a gallon higher than the same week a year earlier. A trip charge set against the older number is now funding a different vehicle.
- What the diesel number is, and where it differs by region
- Why service route fuel costs behave differently from freight
- Recosting a trip charge: five checks on service route fuel costs
- A worked example, with every assumption stated
- Three ways to recover it, and what each one costs you
- What to change in the contract, not just the price list
- The records that make the number visible
- Warning signs and common mistakes
- Should a dealer add a fuel surcharge or raise the base rate?
- How often should the fuel number be rechecked?
What the diesel number is, and where it differs by region
EIA publishes the on-highway diesel average weekly, by national figure and by Petroleum Administration for Defense District (PADD), plus selected sub-regions. The national average for the week ending October 12, 2026 was down 2.0 cents from the previous week, so the short-term direction is not the issue. The twelve-month move is.
| Region, week ending 10/12/2026 | On-highway diesel, dollars per gallon |
|---|---|
| United States | 6.179 |
| East Coast | 5.908 |
| New England | 6.441 |
| Central Atlantic | 6.471 |
| Lower Atlantic | 5.645 |
| Midwest | 6.259 |
| Gulf Coast | 5.809 |
| Rocky Mountain | 6.302 |
| West Coast (PADD 5) | 7.240 |
| West Coast less California | 6.503 |
| California | 8.091 |
The spread matters for anyone quoting a flat rate across a multi-state territory. California at $8.091 and the Lower Atlantic at $5.645 are $2.446 a gallon apart in the same week, which is a different cost per service call for the same drive time. The weekly series is on the EIA Gasoline and Diesel Fuel Update.
A second published number is worth having alongside it. The IRS business standard mileage rate was 70 cents per mile for 2025, 72.5 cents for January 1 through June 30, 2026, and 76 cents for July 1 through December 31, 2026. It is a tax computation rate rather than a billing rate, and whether a particular operation can use it is a question for a tax adviser, but it is a useful outside check on whether an internal cost-per-mile figure is plausible. The rates are published on the IRS standard mileage rates page.
Why service route fuel costs behave differently from freight
Freight on an equipment delivery is a purchased line. It arrives as a carrier invoice, it can be re-rated, and it is visible to everyone on the order. Route fuel is the opposite: it is bought in small amounts by a technician at a pump, spread across several calls, and rarely appears on a customer invoice as itself.
That invisibility is the whole problem. A dealer who would challenge, say, a $180 freight re-rating on a treadmill will absorb a comparable sum across a week of service calls without ever seeing a document that names it.
The second difference is duty cycle. A long-haul gallon moves freight at highway speed and reasonable efficiency. A service gallon is spent on urban legs, in traffic, with the engine idling while a technician works at a tailgate, which is why rated fuel economy is a poor guide for this calculation.
Treat the number as a direct cost of the service line, measured per completed call. That framing is what makes a trip charge defensible to a customer and reviewable internally.
Recosting a trip charge: five checks on service route fuel costs
- Measure actual miles per gallon by vehicle, not by brochure. A loaded box van with a lift gate, running short urban legs with the engine idling at each stop, does not return its rated figure. Pull six months of fuel card gallons against odometer readings.
- Count the miles the route really drives. Use dispatch records, not straight-line distance. Returns to the shop for a part, second visits and a stop at a supply house are route miles.
- Divide by completed calls, not by stops. A diagnosis that ends in a parts order is a call that consumed fuel and may produce no invoice line, so the denominator should be calls that bill.
- Use your region’s price, not the national one. If you run California or Central Atlantic routes, the national average understates your cost per mile.
- Set a review date and a trigger. Decide the move in the weekly EIA average that causes you to reprice, and put the review on a calendar rather than waiting for a bad month.
A worked example, with every assumption stated
The figures below are illustrative assumptions chosen to show the method. They are not survey data and they are not a benchmark for your market. Replace each one with your own records before using the result.
Assume one diesel service van returns 14 miles per gallon in real use, drives 120 route miles in a working day, completes 5 billable calls a day, and runs 250 days a year. That is 8.57 gallons a day.
At $6.179 a gallon, the fuel for that day is $52.96. At the price a year earlier implied by the EIA twelve-month change, $3.665 a gallon, the same day cost $31.41. That $3.665 is derived by subtracting the published change from the published price, so it carries the rounding of two figures given to three decimals. The difference is $21.55 a day, or $4.31 a billable call.
Across 250 days, one van’s fuel moves from roughly $7,854 to roughly $13,241, a difference of about $5,387. A three-van operation on the same assumptions is carrying about $16,161 more a year in fuel alone, before any change in wages, parts or insurance.
That is the number to hold next to your trip charge. If the charge has not moved while service route fuel costs did, the increase came out of gross margin on parts and labor.
Three ways to recover it, and what each one costs you
| Approach | Works best when | The trade-off |
|---|---|---|
| Raise the flat trip charge | Routes are dense and similar in length | Simple to quote, but it overcharges close customers and undercharges distant ones |
| Zone pricing by distance band | Territory spans two or more regions or a wide radius | More accurate, but needs clean mileage data and a published zone map |
| Fuel surcharge tied to a published index | Contract customers who accept an indexed adjustment | Transparent and defensible, but it has to be written into the agreement in advance |
A fourth option is to drive fewer miles for the same revenue, which can be the cheapest of the four. Our analysis of where a service route leaks billable hours covers the scheduling side of that, and the same density gains reduce fuel per call.
What to change in the contract, not just the price list
A flat trip charge inside a signed maintenance agreement generally cannot be repriced mid-term unless the agreement provides for an adjustment. That makes the renewal conversation the real lever, and it makes the surcharge language something to add at renewal rather than to argue about during a term.
Two clauses are worth having. One ties an adjustment to a named published series and a reference week, so the number can be checked. The other sets a review point, typically annual, at which both sides look at the rate.
For operators building the service book from scratch, our guide to building a profitable service route before adding contracts sets out the base structure these clauses attach to.
The records that make the number visible
- Gallons and odometer by vehicle, monthly. Fuel card data against the vehicle log, which gives real miles per gallon rather than a rated one.
- Route miles per completed call. Arguably the most useful single number in this exercise.
- Fuel cost as a percent of service revenue. Tracked monthly, so a change is visible before the year closes.
- Idle time, where telematics report it. Lift gate and diagnostic idling burns fuel that no mileage figure captures.
- Trip charge by customer and effective date. So you know which agreements are still priced on an older fuel number.
If a customer pushes back on a higher charge, the counter-argument is usually about response time rather than price. Our method for measuring documented downtime costs before buying faster service gives the buyer-side arithmetic that makes a premium defensible.
Warning signs and common mistakes
A common mistake is repricing from the national average when the route runs in a high-price district. On the week in question that understated a California route’s fuel by $1.912 a gallon.
A second is using the rated miles per gallon from the vehicle specification. Short urban legs with frequent stops and power-lift operation commonly return less, and the gap compounds across a year.
A third is folding fuel into the labor rate. That hides the cost, makes it impossible to show a customer where an increase came from, and leaves the labor rate carrying a variable it cannot explain.
A fourth is forgetting the fleet rules that attach to larger trucks. If the recosting exercise pushes you toward a bigger vehicle, our explainer on delivery trucks over 10,000 pounds and federal DOT rules covers what changes above that threshold.
Should a dealer add a fuel surcharge or raise the base rate?
It depends on who the customer is. Contract accounts generally accept an indexed surcharge because it is checkable and reversible. One-off residential and small-studio calls often respond better to a single clear trip charge, because a variable line on a small invoice invites an argument that costs more than the money involved.
How often should the fuel number be rechecked?
The EIA series is weekly, but repricing weekly would be unworkable. A monthly read with a written trigger, and a formal rate review at renewal, matches how service agreements actually get signed.
Rechecking service route fuel costs is a single afternoon of work. Pull six months of fuel gallons and route miles, divide by completed calls, and compare the result to the trip charge on your three largest agreements. Whatever the gap is, it has been coming out of margin since last fall.
