Fuel Card Data vs Telematics Fuel Data: Which to Trust?

What Fuel Card Data and Telematics Fuel Data Actually Measure

Both systems describe parts of the same fueling event, but they speak different operational languages. One describes a financial transaction. The other describes what the vehicle was physically doing before, during, and after that transaction.

What Fuel Card Data Captures

Fuel card data usually records dollars spent, gallons purchased, purchase date and time, merchant location, card identification, driver identification or PIN, and product grade. Some card programs also ask the driver to enter the vehicle odometer at the pump. That transaction record makes the card the better authority for how many gallons were purchased and what the fleet paid.

That distinction matters because fuel is still a major operating expense. ATRI reported that the average cost to operate a truck reached a record $2.336 per mile in 2025, while nonfuel costs were $1.854 per mile. The difference puts fuel at about $0.482 per mile.

A fleet fuel management system can organize those transactions by vehicle so managers can compare actual spend rather than relying on receipts or monthly card statements alone.

The weakness is that the financial record does not automatically prove the correct vehicle received the fuel. A valid card can still be used at the wrong vehicle, shared between drivers, or entered with an inaccurate odometer reading.

What Telematics Fuel Data Captures

Telematics starts with the vehicle rather than the payment. GPS and vehicle connections can capture location, actual mileage, engine hours, idle time, harsh driving activity, tank level readings, and fuel consumption information available from the ECM or OBD connection.

That makes GPS tracking and telematics the stronger source for location, distance, engine activity, and how the vehicle operated.

Telematics still does not create a retail transaction record. It can show that a truck stopped at a fuel station and that its fuel level changed, but by itself it does not prove the merchant charge, purchase price, tax paid gallons, or product that appeared on the receipt.

Fuel Card Data vs Telematics Fuel Data at a Glance

The simplest way to choose between them is to match the data source to the question you are trying to answer.

Where Each Data Source Goes Blind

Every fuel report contains assumptions unless another data source can validate it. Managers reviewing fuel performance should know what fleet managers miss in fuel reports before treating every number on a dashboard as equally reliable.

The Limits of Fuel Card Data

A standalone fuel card transaction cannot confirm that the assigned vehicle was physically at the pump. It also cannot measure idle time, route behavior, engine fuel use, or actual distance traveled. The odometer field often depends on a driver manually entering a number.

Industry estimates sometimes put error rates for manually recorded mileage around 15 to 30 percent, although that range is not an IFTA or FHWA regulatory benchmark. FHWA mileage reporting evaluation does confirm that manual odometer reporting introduces reading and transcription errors, while vehicle based systems can automatically capture mileage data.

Card assignment creates another problem. If one card follows a driver across several vehicles, gallons can land against the wrong asset. Linking cards to vehicles through clear fleet user and driver management rules makes asset level fuel analysis much cleaner.

The Limits of Telematics Fuel Data

Telematics has its own uncertainty. Fuel level sensors generally provide an operational estimate rather than the same metered quantity recorded by a fuel pump. Calibration, tank shape, vehicle angle, sensor drift, aftermarket hardware quality, and the signal available from a particular vehicle can all affect readings.

ECM consumption data also should not be mistaken for a purchase receipt. It can help reveal unusual consumption and fuel trends that signal a maintenance problem, but it cannot establish the exact price paid or prove a specific retail purchase.

Which Data Source to Trust for Each Fleet Decision

Do not choose one winner for every fuel question. Choose the source closest to the fact you are trying to verify.

Cost Control, Budgeting, and IFTA Reporting

For fuel spend, cost per gallon, and gallons purchased, trust the fuel card transaction. If the card shows 24.6 gallons at $3.80 per gallon, the recorded purchase cost is $93.48.

IFTA requires both sides. Official IFTA procedures require distance by jurisdiction as well as fuel information, including tax paid fuel purchased in each jurisdiction. Vehicle tracking systems are specifically recognized for producing distance records.

That means the practical combination is fuel card gallons plus trip and mileage tracking for jurisdictional distance. Treating either side casually can create tax reporting problems because a clean fuel statement does not replace mileage records.

Fuel Theft, MPG, and Maintenance Triggers

Fuel theft and card misuse need both sources. Suppose a card records a 28 gallon purchase at 2:14 PM, but GPS places the assigned truck 17 miles from that station at the same time. That location mismatch deserves investigation before anyone debates whether the vehicle's MPG looks normal.

Industry estimates sometimes claim that 19 to 22 percent of fleet fuel spend can be affected by fraud, misuse, or reconciliation errors, with GPS validated transactions reducing some fraud patterns by as much as 80 percent. These are industry estimates rather than government benchmarks, so fleets should use their own baseline and exception history to quantify exposure.

MPG also benefits from both records. Use reliable telematics mileage as the distance input and card gallons as the purchase input, while allowing for fuel already in the tank at the beginning and end of the measurement period. Reviewing fuel card exceptions alongside location and consumption data makes suspicious transactions easier to separate from ordinary data noise.

Maintenance triggers are different. Mileage and engine hours should come from the vehicle data whenever reliable telematics coverage exists. A number typed into a pump keypad should not move a preventive maintenance due date.

How to Reconcile Both Into a Single Source of Truth

The goal is not to force two systems to report identical numbers. It is to establish which record owns each field, then surface meaningful disagreement in one fleet reports dashboard.

For a 50 vehicle fleet, industry estimates often place manual monthly fuel reconciliation at roughly two to three working days, which is why exception based review matters more than checking every purchase individually.

A practical setup follows this sequence:

1. Confirm telematics coverage. Verify that every required vehicle reliably reports GPS location, mileage, and engine hours before using that feed as the operational reference.
2. Connect the fuel card feed. Import transactions from providers such as WEX, Comdata, or Fuelman so gallons, cost, merchant, time, and product data arrive without manual re-entry.
3. Assign cards to vehicles. Keep a stable asset relationship wherever possible instead of letting cards follow drivers between unrelated vehicles.
4. Create location and capacity rules. Compare the merchant location with the vehicle position and compare gallons purchased with usable tank capacity. A 31 gallon purchase for a vehicle with room for only 18 gallons should become an exception.
5. Set variance thresholds. Define tolerances for location distance, transaction timing, MPG change, tank capacity, duplicate purchases, and unexpected fuel grade.
6. Send only meaningful alerts. AUTOsist can bring fuel management software, GPS data, fuel card feeds, and reporting together so managers investigate exceptions rather than manually comparing separate exports.
7. Review exceptions weekly. Resolve incorrect vehicle assignments, bad odometer entries, sensor issues, legitimate unusual purchases, and suspected misuse while the event is still easy to verify.

Turning Two Data Streams Into Better Fleet Decisions

Use the fuel card for what it proves: gallons purchased, dollars spent, merchant activity, and transaction details. Use telematics for what it proves: vehicle location, mileage, engine hours, idle activity, and operating behavior.

The overlap is where the real control comes from. A transaction that agrees with the vehicle's location, capacity, mileage, and expected consumption usually needs little attention. A transaction that conflicts with those signals deserves review. That approach turns fuel management from monthly spreadsheet cleanup into a repeatable exception process that protects budgets, reporting accuracy, and maintenance decisions.