Fuel is a fifth to a quarter of fleet cost
ATRI's annual Operational Costs of Trucking studies have put fuel near a quarter of truck operating costs year after year, second only to driver compensation. The EIA publishes a weekly retail on-highway diesel average for the country, and state-level series too. A fleet that does not know where its fuel price sits against that weekly average is pricing blind.
The fuel line has three parts: the price per gallon, the gallons burned, and the gallons that disappear without burning. Most oilfield fleets manage the first part with a card program and ignore the other two.
Buying fuel like a business
Bulk fuel agreements and fuel cards only help if someone compares the negotiated price to the market every week. Diesel swings with crude and crack spreads, and a fixed discount off a moving average behaves differently from a fixed price. The discipline is to know the effective price per gallon at every point of use, from the fuel island to the pump at the truck stop.
Fuel islands on a yard or a pad need the same controls as the card program: driver identification, odometer or engine hours at fill, gallons dispensed, and a tank that reconciles to a dip or a gauge. A fuel island without reconciliation is a hole in the yard.
Idling is the silent line item
An idling truck burns fuel to do nothing. In cold weather the engine runs to keep the cab warm and the air system charged. In the Permian summer it runs to keep the cab cool. Either way it is a gallon per hour or more on a class 8 truck, and a fleet that idles 20 trucks overnight is burning a small fuel budget before the first load of the day.
Automatic engine shutdown, auxiliary power units, battery heaters, and route planning that gets trucks home instead of parked on location all cut idle hours. The first step is measuring them: engine hours against odometer miles tells any fleet exactly how much of its fuel went to idling.
Theft and unauthorized use
Fuel theft in oilfield fleets rarely looks like a heist. It looks like a driver filling a personal truck, a tank dip that does not match the dispenser, or a fuel card used for non-fuel purchases. Card controls, per-driver PINs, purchase category limits, and daily exception reports catch most of it. The rest is caught by making the data visible: when gallons per load start drifting, someone asks why.
The data view that matters
Gallons per hour, miles per gallon, idle percentage, and effective price per gallon are the four numbers that manage fuel. Most fleets have the data in their telematics and their card statements; few have combined them into one view per truck, per driver, per week.
Fuel data also crosses into billing. When standby and waiting time are billed against the customer, the fuel burned during that standby is part of the cost of the wait. Fleets that cannot see the connection price jobs blind.
If fuel spend is still reconciled at month end with a variance you cannot explain, an operations review will find the leak.