GPS Tracking for Tanker Trucks (Citerne)

What this page covers Why liquid-tanker fleets need a GPS stack with in-tank level monitoring, siphoning detection, and route-locked geofence, beyond the standard truck GPS. The pain points fuel and water distributors actually face, the sensor stack that resolves them, audit exports for tax and customer use, and pricing for West African operations.

Key takeaways

• Siphoning is the dominant theft pattern. A driver stops on the route, transfers 50-200 L of fuel into a side container, continues delivery. Without an in-tank level sensor, you find out when the customer measures their delivery and disputes the volume. By then it's too late to recover.
• Volume reconciliation is the operational deliverable. What was loaded vs what was delivered, per shipment, per route. The GPS platform should output this automatically.
• Geofence on delivery routes is non-optional. A tanker that deviates from the planned route is either a personal-use trip, a fraud event, or an unscheduled customer addition, all of which need operator visibility.
• Engine cut on hardwired tankers is a recovery tool, not a deterrent. Tanker theft is rare (the truck is conspicuous, the cargo is regulated), but cargo theft via siphoning is common and a different problem.
• Tax audit exports matter for fuel distribution. Government tax authorities increasingly request distribution records for excise verification. Auto-generated exports save staff time and improve compliance posture.

Outline

1. Why tanker GPS is different
2. In-tank level sensors and siphoning detection
3. Route geofence and corridor compliance
4. Volume reconciliation and audit exports
5. Use cases by cargo type
6. Pricing in FCFA
7. Buyer's checklist

Why tanker GPS is different

A tanker truck has a different risk profile than a dry-cargo truck.

Cargo is fungible and high-value-per-volume. 1,000 L of diesel is worth ~700,000 FCFA at retail, weighs only 850 kg, and is essentially impossible to identify after transfer. This is the perfect siphoning target: small volumes disappear without obvious signs, and the recovered cargo blends instantly into another tank.

Volume measurement is the unit of trust. Tanker contracts pay on volume delivered, often with reconciliation at both ends. The customer measures incoming volume; the supplier records outgoing volume; any difference is a dispute. GPS platforms that don't surface in-tank volume data leave operators arguing with customers about what actually arrived.

Routes are predictable but not enforced. A tanker on a Dakar → St-Louis route follows a known corridor. Deviation from the corridor is the operational signal: not by minutes (truck stopped for fuel) but by route shape (truck went through a quartier where it has no business). Standard truck GPS can show this; tanker GPS makes it actionable.

Regulatory exposure. Fuel distribution is taxed and licensed. Tax authorities require documentation. A GPS audit log, exportable per shipment, is the artifact that satisfies the inspection.

In-tank level sensors and siphoning detection

The core sensor for tanker GPS is the in-tank level probe: a calibrated sensor in the tank that reads liquid volume continuously.

Two main probe types:

Capacitive level probe. Standard for fuel and water tanks. Continuous reading, accurate to ~1-2% of tank capacity. Calibrated against the tank's geometry (the relationship between liquid level and volume isn't linear in a cylindrical tank).

Ultrasonic level probe. Non-contact, mounted on the tank ceiling. Useful for chemical tanks where contact sensors aren't an option. Slightly less accurate, more expensive.

The platform reads the probe at every position update (typically every 10-30 seconds) and computes:

• Volume at start (calibrated reading at pickup)
• Volume at finish (calibrated reading at delivery)
• Volume curve along the route
• Detected events: deliveries (volume drops at known customer geofence), siphoning candidates (volume drops outside a geofence, with engine off)

A "siphoning candidate" alert fires when volume drops by more than a configured threshold (e.g. 30 L) while the truck is stationary, engine off, outside any registered customer geofence. Operator gets the alert with the GPS location. Investigation can happen the same day, not a week later.

Route geofence and corridor compliance

For tanker fleets, geofence is configured at three levels:

Origin and destination geofences (depot and customer sites). Volume reconciliation events are anchored to these geofences: the volume measured at depot exit is the official "loaded" reading; the volume at customer arrival is the "available for delivery" reading.

Corridor geofence (the planned route). A polygon along the planned route, typically 1-5 km wide. Alerts fire on exit. The exit alert distinguishes between intentional detour (driver took a known shortcut) and unintentional/unauthorized deviation.

Forbidden-zone geofence (no-go areas). Sometimes a fleet operator configures alerts on entry into specific quartiers or known siphoning hotspots. Less common but useful in markets with well-known fraud patterns.

Volume reconciliation and audit exports

Per-shipment audit log structure:

• Shipment ID + cargo type + product (diesel / petrol / water / chemical specifics)
• Depot loading: timestamp + GPS + initial volume + theoretical density
• Route: continuous time-series of GPS + volume + speed
• Customer arrival: timestamp + GPS + volume on arrival
• Customer-confirmed delivery: timestamp + final volume + confirmed delivered volume (may match arrival or be lower if customer confirms a partial fill)
• Reconciliation: loaded - delivered = expected loss + actual loss (with anomaly flag if deviation > threshold)

The export is a PDF (for customer copy + tax filing) or a CSV (for ERP / accounting integration).

Operators handling 50+ daily shipments wire the export to API: every completed shipment auto-generates the audit document and pushes it to the ERP.

Use cases by cargo type

Diesel and petrol distribution

The dominant tanker use case in West Africa. Distributor delivers fuel to retail stations, industrial customers, mining sites, and fleet operators. Pain points:

• Siphoning during transit (especially long routes to remote customers)
• Volume disputes at customer reception
• Tax compliance (excise duty paid per delivered volume)

Stack: hardwired GPS + in-tank level probe + corridor geofence + volume reconciliation export.

Water distribution

Bulk water delivery to construction sites, isolated communities, industrial users. Less theft risk (lower per-volume value) but high operational complexity (multi-customer routes, partial deliveries, payment-on-volume contracts).

Stack: hardwired GPS + in-tank probe (lower-spec is fine) + customer geofence + volume reconciliation export.

Industrial chemical transport

Specialty chemicals, sometimes hazardous. Regulatory exposure is high (transport licenses, route restrictions, time-window restrictions). Stack: hardwired GPS + ultrasonic level probe (chemical compatibility) + strict corridor geofence + audit export with regulator-specified format.

Fuel-tank tracking for own-fleet refueling

Some operators own a tanker not for distribution but for refueling their own truck or generator fleet. Use case is internal: track that the on-board fuel is going where it's supposed to go. Stack is the same as distribution but with all customer geofences pointing to your own depots.

Pricing in FCFA

Tanker GPS is more expensive than baseline truck GPS due to the level probe and calibration:

Initial probe calibration is a one-time service, typically 2-4 hours per truck at our installer network. Annual recalibration is recommended for fuel-distribution operators.

Buyer's checklist

• In-tank level probe (capacitive or ultrasonic, calibrated)? Yes.
• Siphoning candidate alert (volume drop with engine off, outside geofence)? Yes.
• Corridor geofence with deviation alert? Yes.
• Per-shipment volume reconciliation export (PDF + CSV)? Yes.
• Sub-minute GPS + volume sampling rate? Yes.
• Customer-site geofences for arrival/departure events? Yes.
• API for ERP integration? Yes.
• Calibration service + annual recalibration support? Yes.
• Engine cut on hardwired install? Yes.
• Hazardous-chemical-compatible ultrasonic option? Yes.

Next steps

• See base truck GPS for the dry-cargo equivalent
• See refrigerated GPS for cold-chain audit-export pattern
• Browse logistics & delivery industry page
• Read the FR truck-fleet pillar for broader logistics context
• Tanker fleets typically go through Enterprise: /enterprise or [email protected]

A 15-minute call evaluates your route profile, cargo type, and level-probe needs, then prices out a deployment.