Post-grant operations
How fuel card discounts work
Every fuel card advertises cents off per gallon, but the discounts come from two different pricing models: cost-plus, built up from the station's wholesale cost, and retail-minus, cut down from the posted pump price. This page explains both models, what a pump price contains, and why the same card saves different amounts at different stops.
By Evan Reid, Founder of Haul Handbook · Updated Jul 22, 2026
What a pump price contains
The posted price at the island is a stack, not a single number. EIA's gasoline and diesel fuel update reports that for March 2026, crude oil made up 42 percent of the retail price of a gallon of on-highway diesel, refining 34 percent, distribution and marketing 12 percent, and taxes 12 percent.The last slice of that stack, the distribution and marketing share, contains the truck stop's own margin, and that margin is the raw material every fuel card discount is carved from. A network cannot discount the crude, the refining, or the taxes; it can only negotiate against the retailer's piece.
Cost-plus vs retail-minus
Cost-plus pricing starts from the station's wholesale cost of the fuel that day and adds a fixed markup. Your price floats with the wholesale market rather than the sign out front, so when a station posts a high retail price over a cheap wholesale cost, cost-plus buyers capture the difference. When retail is priced thin, the same card can save little or nothing at that stop.
Retail-minus works from the other end: the posted pump price minus a negotiated amount. It is easier to verify at the island, but it inherits whatever the station decided to post that day; a station can raise retail and quietly shrink what the discount is worth.
Vendors use exactly this vocabulary in their own marketing. Mudflap claims cost-plus discounts of up to a dollar off each gallon nationwide, with more than 515,000 drivers using it and over $1 billion in claimed driver savings since 2020; discounts vary by stop and market conditions.
The reference price matters too, because truck stops post separate cash and credit prices for diesel. TCS claims an average saving of 59 cents on each gallon, a figure the site attributes to actual in-network client transactions for the second quarter of 2026, with a never-pay-more-than-cash-price promise at more than 12,000 accepted locations.
Why the advertised numbers vary
Because the spread being shared is different at every station on every day, no vendor can honestly promise a fixed saving, which is why the published figures are averages or maximums. AtoB's published discount claim averages 42 cents off each gallon of truck diesel and 5 cents off each gallon of unleaded through its discount network, a vendor-stated average that varies by station. RTS claims an average saving of 45 cents on each gallon at more than 4,000 fuel stations nationwide, a vendor-stated average.
None of those figures contradict each other, and none are verifiable from the outside: each is the vendor's own summary of its own network, computed its own way. Treat them as claims to test against your lanes, not as prices.
Where to go from here
With the mechanics in hand, the programs that publish their fees and terms are compared in the fuel card comparison. Remember that the tax slice of every gallon is separate machinery: it settles through your quarterly filing against the current IFTA rates, whatever card you fuel with. And if you are still standing up your operation, fuel decisions sit alongside the rest of your first 30 days with new authority.
Frequently asked questions
How do fuel card discounts work?
- A fuel card network negotiates pricing with truck stops, then passes part of the spread to the cardholder. Cost-plus programs price your fuel up from the station's wholesale cost; retail-minus programs price it down from the posted pump price. Which model applies, and at which stations, is what actually determines your savings.
Are advertised per-gallon savings guaranteed?
- No. Published figures are vendor-stated averages or maximums, not guarantees. For example: AtoB's published discount claim averages 42 cents off each gallon of truck diesel and 5 cents off each gallon of unleaded through its discount network, a vendor-stated average that varies by station.
What is the difference between the cash price and the card price?
- Truck stops post separate cash and credit prices for diesel, and fuel card discounts are usually quoted against one of them, so the reference price matters as much as the discount. One vendor's published framing: TCS claims an average saving of 59 cents on each gallon, a figure the site attributes to actual in-network client transactions for the second quarter of 2026, with a never-pay-more-than-cash-price promise at more than 12,000 accepted locations.
Why does the same card save different amounts at different stops?
- Because the underlying spread differs stop by stop. A station's wholesale cost, its posted retail price, and the network's negotiated terms all move independently, so a cost-plus discount that is deep at one truck stop can be shallow at the next one down the highway.
Sources
Primary statutes and official agency pages this guide relies on. Laws and fees change, so confirm against the current source before you act.
- Gasoline and Diesel Fuel Update: What Consumers Pay for a Gallon of On-Highway Diesel · U.S. Energy Information Administration (EIA)
- AtoB Fuel Cards: Plans and Fee Comparison · AtoB
- TCS Fuel Card · TransConnect Services
- Mudflap: Diesel Discount Network · Mudflap
- RTS Fuel Cards · RTS, Inc. (Shamrock Trading Corporation)
Haul Handbook publishes educational information about trucking registration and compliance requirements. This is not legal, financial, or tax advice. Rules, fees, and deadlines change; confirm with the agency before you file or pay.