How to stop fuel theft in your fleet

Fuel rarely leaves in one dramatic theft. It goes a few litres at a time, across many fills, until the month's diesel bill stops matching the work the fleet did. On 23 September 2026 the Petroleum Planning and Analysis Cell put diesel in Delhi at Rs 95.20 a litre at an IndianOil outlet, so twenty litres a week off one truck is real money.

Each pattern leaves its own trace. Siphoning shows in the tank, an inflated bill as a gap between the bill and the tank, padding in the trip. A system that works needs all three records.

• Siphoning from parked vehicles: a tank drawn down overnight at a yard or a customer gate, a few litres at a time so the gauge barely moves.
• Inflated fuel bills: a bill written for more litres than went into the tank, the difference settled in cash.
• Card misuse: a card used for another vehicle, a jerrycan or a private car, or swiped for litres that never reach the tank.
• Route padding: extra kilometres driven or claimed so a bigger fill looks reasonable.
• Idling: engines left running through loading, waiting and rest halts. Not theft, but fuel you paid for that moved nothing.

Cash fills are the hardest to check, so move every fill you can onto fleet fuel cards. Where your provider allows it, issue the card to the vehicle rather than the driver, and switch on every authentication option it offers. A card tied to a vehicle makes each transaction answerable to one trip.

Then bring everything into one fuel ledger: card statements, cash receipts, the driver's log of odometer and litres, and tank readings if you have sensors. Every entry should carry the vehicle, the driver, the date, the pump and the odometer. An entry that cannot be matched to a vehicle and a trip is an exception to explain.

Keep the rules short enough to remember. No bill, no reimbursement, and the bill must show litres, rate and vehicle number. Agree approved pumps on each regular route, because fewer pumps are easier to audit.

Indian fleets have a right most drivers never use. IndianOil's citizen charter for retail outlets says all retail outlets must keep a calibrated five litre measure, stamped by the Weights and Measures Department every year, and asks customers to call for it whenever the quantity delivered is in doubt. It puts the permissible variation, where a dispensing unit malfunctions, at plus or minus 25 ml in five litres, to be rectified immediately. The charter is IndianOil's own, so at another company's pump ask what its charter says.

The charter also notes that dispensing units are sealed and calibrated every year by that department, but that tampering or malfunction is not ruled out. For quality it describes a density check for petrol and diesel: fuel from the nozzle into a 500 ml jar, a calibrated hydrometer and thermometer, the reading converted to density at 15 degrees centigrade and compared with the outlet's reference register. The filter paper test is for petrol only.

Weights and measures sit under the Legal Metrology Act, 2009, in force since 1 April 2011. This is general guidance, not legal advice, and complaint routes differ by state.

• Note the meter reading before delivery starts and the final reading after it ends.
• Switch the engine off before taking delivery, which the charter requires, because spillage near a running engine is a fire risk.
• Ask for the stamped five litre measure when a delivery looks short, and for the density check when a tank empties faster than usual.

A bill tells you what was paid for. Only the tank tells you what arrived and what later left. Public service vehicles and national permit vehicles already have to carry an AIS-140 tracking device with a panic button under Rule 125H of the Central Motor Vehicles Rules, 1989. What applies to older vehicles, and to goods carriages without a national permit, varies by state. What is usually missing is a fuel reading precise enough to reconcile against.

Where the vehicle's own reading is too coarse, fit a tank level sensor and wire it to a tracker with RS232 or RS485 inputs. ZonePin Fleets reads Teltonika's FMB (2G) and FMC (4G LTE) trackers out of the box, and the supported trackers page lists which models carry those interfaces — check a model's lifecycle status with us before you buy for a whole fleet. How many sensors one tracker takes depends on the model, which matters on trucks with two tanks.

• Calibration: the sensor reports a level, not litres. Build a level to litres table for each tank by adding fuel in measured batches and recording the reading after each.
• Noise: fuel moves on bad roads and settles differently on a slope. Watch a parked vehicle for a week and learn the band your readings wander through before setting a threshold.
• Installation: opening a fuel tank is skilled, hazardous work. Use a trained installer, and seal the probe and wiring so tampering leaves a mark. If the change might need approval, ask your RTO or state transport department first.

Reconciliation is arithmetic, not software. For each vehicle, compare the litres bought with the distance run and with that vehicle's own settled figure for kilometres per litre. Compare a vehicle with itself, not with the fleet, because load, terrain and traffic all move the number honestly. A steady vehicle that suddenly needs more diesel for the same run is worth chasing.

Ask three questions of every fill. Did the tank level rise by roughly the litres billed? Was the vehicle at that pump at that time? Does the distance since the last fill explain the litres? One failure can be a glitch. Two together, repeating, is a pattern.

• Vehicle position and ignition state at the transaction time, checked against the pump named on the bill.
• Distance since the last fill against that vehicle's normal consumption band for that kind of run.
• Fills away from the agreed route, or repeat fills sitting just under an approval threshold.

Siphoning happens while a vehicle stands still, and the signature is hard to argue with: the level falls while the ignition is off and the odometer does not move. Build your first alert on exactly that, not on every fluctuation, or the team will learn to ignore alerts.

Then add two more. One for the slow siphon, comparing the level at the start of each day across a week, because a few litres a night hides inside a single day's noise. One for a fill larger than the tank can hold. Set thresholds above the movement you measured on parked vehicles, and start with a few vehicles before turning a rule on for the fleet.

Decide in advance what the first hour looks like. Name the person on call, have them ring the driver, ask for a photograph of the cap and filler, and record the location and time beside the alert. A confirmed theft goes to the police, and a place that produces repeat alerts deserves a zone of its own.

Some of the missing fuel was never stolen. The Energy Management Centre of the Government of Kerala collects the general motoring figures: smooth, gradual acceleration can give as much as a 20% gain in fuel economy against an aggressive style, tyres at the maker's maximum recommended pressure as much as 6%, a figure it quotes from the US Environmental Protection Agency, and dirt or gravel can rob up to 30% of mileage. Those are car figures, a direction rather than a promise for a loaded truck. It also makes the point drivers resist most: idle longer than ten seconds and you burn more fuel than restarting the engine.

Turn that into a written rule for loading bays, queues and long waits. Delhi's Department of Environment has run a public awareness campaign called Red Light On Gadi Off at the city's intersections since 2020. Rules stick when they are priced, so convert idle minutes into rupees per vehicle and driver.

Finally, treat an unexplained drop as a question, not a verdict. Sensors glitch, tanks leak and yards slope. Write a one page fuel policy every driver signs, covering cards, pumps, receipts, engine-off rules and what happens when a loss cannot be explained. Share each driver's own numbers with them, take advice on the employment rules before deducting from pay, and say something to the drivers whose figures stay good.