Fuel level sensor vs CAN bus
There are two ways to read how much fuel a vehicle holds. An in-tank fuel level sensor measures the liquid directly through a probe in the tank; the CAN bus reads the fuel figure the vehicle's own electronics already publish. Both feed Trakora's theft and consumption engine — and the right choice depends on your vehicles, not on an accuracy number in a brochure.
Fuel sensor options at a glance
- Option A
- In-tank fuel level sensor (probe)
- Option B
- CAN bus read from the vehicle
- Sensor accuracy
- — not published — test on your tank†
- CAN accuracy
- — depends on the vehicle†
- What Trakora is
- The telemetry, theft and consumption layer over either input
- Theft signal
- fuel_drop_stationary — siphoning while parked
- Health signal
- fuel_signal_offline — sensor stopped reporting
- Best fit
- Decided per vehicle type, not one-size-fits-all
- Who it's for
- Fleet, construction, mining and transport operators
Read the tank, or read the vehicle
They measure different things, and that difference — not a headline accuracy figure — is what decides which one belongs on which vehicle.
In-tank fuel level sensor
A capacitive or float probe is installed into the fuel tank and reports the liquid level directly. It sees the fuel itself, which is why it is the standard choice where the vehicle offers nothing useful electronically.
- Works on almost any tank — trucks, plant, gensets, older vehicles with no data bus
- Sees the actual liquid, so a siphon shows as a real level drop
- Needs installation into the tank and calibration to the tank's shape
- Sensitive to fuel slosh on rough roads, which good filtering has to handle
CAN bus read
The vehicle's own electronics already compute a fuel level and rate; the CAN bus makes that data available. Reading it means no probe in the tank — but you inherit whatever the vehicle chose to publish, at whatever resolution it uses.
- No tank intrusion — reads data the vehicle already produces
- Fits modern trucks and equipment with an accessible, documented bus
- Depends entirely on the make, model and what the manufacturer exposes
- Not an option where the bus is absent, locked, or does not publish fuel
The honest comparison
The accuracy rows read — on purpose. That blank is the most honest thing on this page.
| Dimension | In-tank level sensor | CAN bus read |
|---|---|---|
| What it measures | The liquid in the tank, directly | The fuel figure the vehicle publishes |
| Tank intrusion | Yes — probe installed into the tank | No — reads the existing bus |
| Vehicle types | Almost any tank, incl. plant and gensets | Modern vehicles with an accessible bus |
| Calibration | Calibrated to the tank shape | Uses the vehicle's own scaling |
| Siphon visibility | Sees a real level drop | Only as good as the vehicle's own reading |
| Accuracy | —† | —† |
| Resolution / drift | —† | —† |
What it measures
Tank intrusion
Vehicle types
Siphon visibility
Accuracy
The accuracy and drift cells are — deliberately. No supplier publishes a fuel-sensor accuracy figure that survives contact with a real tank on a real road, and Trakora will not invent one. Accuracy is a property of your specific tank shape, fuel, sensor and vehicle — the only honest number is the one measured on your own vehicle during a trial, which we will help you run.
What Trakora does with the signal
Whichever input you choose, the value of the system is the engine that reads it. Two shipped rules carry it — for each: what fires it, what the operator sees, what they do next.
The tank fell sharply while the vehicle was parked
A vehicle that is not moving and not running should not be losing fuel. A sharp drop while stationary is the classic siphoning signature — and it is the same signature whether the level came from a probe or the bus.
Tank level falls sharply while the vehicle is parked and not consuming fuel.
A theft signal against the vehicle, time and place — feeding the two-state case chain (theft.suspected → theft.confirmed).
Review the drop against the parked location and time, and act on evidence — a case they can take to a disciplinary, not a hunch.
The fuel sensor stopped reporting
A sensor that goes quiet is either a fault or a cut — and either way the fleet needs to know, because a blind tank cannot be reconciled or protected.
The in-vehicle fuel sensor or bus feed stops reporting its value.
A device-health alert distinct from a theft event, so a failure is never mistaken for a drop.
Check the vehicle rather than trusting silence; a sensor cut before a siphon is itself a red flag.
What a fuel sensor cannot promise you
What to expect
- No accuracy figure is published here because none would be true for your fleet. The number that matters is measured on your own tank and vehicle, in a trial — not read off a spec sheet.
- A level sensor sees fuel slosh on rough roads; the engine filters it, but a single instantaneous reading is never the whole story — the drop pattern is.
- A CAN bus read inherits the vehicle's own resolution and honesty. If the manufacturer publishes a coarse figure, no software makes it finer.
- CAN is only available where the bus is present, accessible and publishes fuel. Many older vehicles and much heavy plant simply do not — those get a level sensor.
- This module reports and detects; it is not a certified metrology device and does not replace a legally-required fuel meter calibration.
The recurring point of this page: accuracy belongs to your hardware and your vehicle. Trakora scopes a short trial so you see the real reading before you commit — the only accuracy number worth trusting.
Frequently asked questions
Which is more accurate, a fuel level sensor or CAN bus?
There is no honest single answer — it depends on your tank, your vehicle and the road. That is why this page shows — for accuracy and offers a trial on your own vehicle instead of a brochure figure.
Why won't you just tell me the accuracy?
Because any single figure would be misleading. Accuracy changes with tank shape, fuel, mounting, road roughness and, for CAN, the vehicle model. We would rather measure it on your fleet than quote a number that fails in the field.
When should I choose a level sensor?
When the vehicle offers no usable data — older trucks, heavy plant, generators — or when you want to see the liquid directly. It works on almost any tank.
When is CAN bus the better fit?
On modern vehicles with an accessible, documented bus that publishes fuel, where you would rather avoid opening the tank. It is not available where the bus is absent or locked.
Can I mix both across one fleet?
Yes. A mixed fleet often runs level sensors on plant and older trucks and CAN reads on newer vehicles, all feeding the same theft and consumption engine.
Does the sensor choice change how theft is detected?
No. Both feed the same fuel_drop_stationary siphoning signal and the same case chain. The input differs; the detection logic does not.
More on fuel theft detection
Not sure which sensor your fleet needs?
Tell us your vehicle mix and we will recommend level sensors, CAN reads, or a blend — and scope a short trial so you see the real reading on your own vehicles before you commit.