What is Siphon Detection in a Fuel Tank?

When a vehicle owner or fleet is parked in the middle of nowhere and there is a fuel leak, it could be catastrophic. The main thing you need to know is that fuel tank siphoning can happen anywhere and at any time. Siphoning may start in the body of your car or truck, but it could also start at the gas station from where it continues until it reaches your car.

Fuel is a substantial cost for any trucking fleet. As a fleet manager, you must have standby systems in place to ensure that your fleet does not overpay for one of its significant operating expenses—fuel.

Fuel leakage and fuel theft may be causing more harm than you realize. Siphon detection is a process to eliminate the risk of fuel theft, which is one of the most rampant crimes in the world today. In this blog, we shall discuss siphon detection in a bit detail as well as how you can use it to prevent theft from happening to your fleet.

What is Fuel Tank Siphoning?

The act of physically emptying the components of your car’s fuel tank is known as fuel tank siphoning. It is accomplished through the use of your mouth, a plastic tube, and the forces of suction and gravity. Criminals frequently use it to steal gasoline and diesel from cars, motorcycles, vans, and trucks. But understanding how to siphon gas isn’t just for petty thieves; it’s also used to transfer fuel from one vehicle to another with the permission of the car owner.

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How is Fuel Syphoned from a Tank?

Fuel tank siphoning is a critical skill that can be used for more than fuel theft. It also applies to any situation in which liquids must be transferred from one container to another. Siphoning works by inducing a vacuum that causes water to flow from one point to another. 

So, if you find yourself fuel tank siphoning to assist someone who has run out of gas, here’s how to siphon some fuel to keep you going. All you need is a container to siphon into and enough hose to reach the container from the inside of the car’s gas tank.

1: Remove the gas cap from your car and insert one end of your hose into the tank.

2: Prepare your container by opening it and filling it.

3: Suck on the hose end like a straw (if it’s a clear hose, wait for fuel to flow through the tube toward your mouth).

4: As soon as fuel enters your mouth, transfer the pipe end from your mouth to the container.

5: Spit out any remaining fuel in your mouth and immediately rinse with clean water.

6: To continue siphoning, keep the container below the level of the fuel tank.

How to Detect Syphoning from a Fuel Tank?

Fuel tank siphoning is the removal of fuel from a company’s asset (the fuel tank in the truck or the on-site fuel storage tank) and placement in a vehicle or container not owned by the company. You can use ELD data to detect irregularities after the fact, but you won’t be able to learn when or who syphoned the fuel — that requires a real-time telematics device. 

There are two popular alternatives:

  1. CAN Bus: The CAN (controller area network) bus is a common communication technology found in the majority of modern light vehicles and trucks. It enables an onboard web browser to receive data from sensors fitted by the manufacturer in the fuel tank. A GPS tracking device is required to send this data to your fuel management system.
  2. Fuel Level Sensor: A fuel level sensor is equipment that is installed in the fuel tank of a vehicle. When there is a fuel loss, the system notifies the fleet manager and the driver. Furthermore, variations in fuel consumption can reveal idling time and be used in driver behavior analytics.

What Effects does Fuel Tank Siphoning have on Business?

Properly managing fuel spending is critical for fleet managers, but with many fleet reporting an increase in fuel fraud in past years, doing so quickly and successfully has become a daunting task. 

  • When these fuel tank siphoning costs are added up, they can have a significant impact on the company’s bottom line and cause funding issues for the fleet department.
  • Illegal pipeline tapping or siphoning can frequently result in oil spills and explosions, with devastating consequences for soil and water pollution.
  • Syphoning may also result in fuel adulteration, which is the process of mixing fuel with other preservatives before selling it at full price and is known to have a negative impact on the environment. 
  • The use of uncontrolled substances in fuel causes the emission of polluting elements, thereby deteriorating air quality.

How Can a Fleet Manager Prevent Fuel Syphoning?

If your vehicle’s fuel economy is rapidly detonating, you should look into the problem. There are several steps you should take to minimize or prevent fuel tank siphoning.

  1. Fleet managers should teach and discuss with drivers the threat of fuel theft and how it affects fleet profitability. Drivers should be conscious of any systematic approach devised by their fleet manager to combat threats such as fuel theft to minimize fuel losses.
  2. Fleet owners must establish fuel benchmarks to analyze their fleet’s fuel consumption situation. If the consumption is high in comparison to the benchmarks, they can investigate to determine the true cause.
  3. Anti-siphoning devices help to prevent unauthorized access to the fuel tank, thereby preventing fuel tank siphoning. If you want to Prevent Fuel Theft, you should use Anti Fuel Theft Devices in conjunction with a Fuel Monitoring System.
  4. You can use the monitoring software to keep track of your fleet’s current fuel level as well as the amount of fuel entering the tank. These insights aid in the estimation of fuel consumption benchmarks for improved fuel efficiency.
  5. Vehicles should be parked in such a way that access to the fuel tanks is obstructed. This Defensive Parking method adds another layer of security, discouraging fuel thieves from stealing.


To help mitigate the risk of fuel theft and siphoning, fleets can use a fuel consumption monitoring system, such as the LocoNav Fuel Monitoring platform, which provides comprehensive fuel monitoring and fuel card solutions.

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