The fuel-margin math every operator should run weekly.

The formula nobody writes down

Realized fuel margin per gallon, per grade, per station, per period:

Margin/gal =
  Retail price/gal
  − Wholesale cost/gal (DTW or rack price + freight + supplier markup)
  − Excise tax pass-through/gal (federal + CA state)
  − Credit-card processing cost/gal
    (= (Retail × interchange %) ÷ gallons sold on card)
  − Shrinkage allocation/gal
    (= dollar value of unattributed wet-stock loss ÷ total gallons)

Run this per grade. Run it per station. Run it weekly. The dashboard math is not new; the discipline of actually looking at it weekly is what separates the operators who hold margin from the ones who lose it slowly.

Where realized margin drifts from target

1. Wholesale price moves the operator didn't catch

DTW (delivered-to-wholesale) prices move daily. A 2-cent increase from your supplier costs you $200/day on a 10,000-gallon-day station if you don't reprice. Most operators reprice weekly or after a competitor moves; the lag between wholesale increase and retail response is the most consistent margin leak we see.

2. Wet-stock loss

Inventory in the tank doesn't equal inventory dispensed at the pump. The three reconciliation points:

• BOL → ATG. The delivery quantity on the bill of lading should match the ATG (automatic tank gauge) reading after the delivery, accounting for temperature correction. If not, you didn't get the volume you paid for.
• ATG → pump totalizer. The drop in tank inventory between two consecutive ATG readings should match the volume the pumps dispensed during that window. If not, you have a leak, a meter calibration issue, or theft at the pump.
• Pump totalizer → POS. Every gallon dispensed should correspond to a sale at the POS. If not, you have drive-offs (customer left without paying) or attendant comping fuel without recording it.

3. Credit-card mix

Credit-card transactions cost interchange (typically 2.0–2.6% on fuel). If your cash-vs-card mix shifts toward card, your per-gallon margin compresses without anything else changing. Operators who run loyalty programs that incentivize cash (the “cash discount” model) can hold margin against a creeping card share.

4. Mix shift across grades

Premium and diesel typically carry wider per-gallon margins than regular. If your customer base shifts toward regular (recession indicator, also a price- sensitivity indicator), your blended per-gallon margin drops even though your per-grade margins held. Track the mix shift independently so you don't mistake it for an operational problem.

The weekly fuel review, what to actually look at

15 minutes a week, per station. The minimum:

1. Per-grade realized margin vs. last week, vs. target.
2. Wholesale cost moves in the last 7 days, did you catch them with a reprice?
3. BOL → ATG → POS reconciliation for the week. Any unexplained variance?
4. Card share % and trend.
5. Mix shift across grades.

A good back office surfaces all five in a single screen. Without it, the operator is pulling four reports from three systems and doing the arithmetic in their head.

What this changes about how you operate

Once the weekly review is a habit, three behavioral shifts happen:

• Repricing decisions get faster. Wholesale up 2 cents Monday morning, retail up 2 cents Monday afternoon, instead of Thursday afternoon when you noticed at month-end.
• Wet-stock investigations become routine. A 0.5% loss for one week is a heads-up; for two consecutive weeks it's a work order to a fuel-system inspector. You catch leaks before they become regulatory issues.
• Per-grade pricing strategy actually gets used. Premium goes up faster than regular when wholesale moves; diesel pricing decouples from gasoline during commercial-truck demand spikes. You have the data to do this; the weekly habit creates the discipline.