Fuel flow meters in vehicle telematics – profit or headache?

FLS vs. fuel flow meters

Fuel consumption monitoring is, probably, the next important task for construction machinery telematics after GPS position tracking. Current situation on telematics market shows, that majority of integration companies offer fuel level sensors (FLS) as a solution of fuel consumption monitoring. The reason is relatively low purchasing and installation costs (100€ to 300€ depending on product and region of installation). Straight off the installation a fleet owner gets overview on fuel tank fill-up and syphoning.

When speaking about fuel consumption monitoring through FLS, it worth to mention several disadvantages of this type of solution (it applies to any FLS in the world):

  • It will not give you fuel consumption data in short term (1 hour – is a minimum period when fuel level change in fuel tank is noticeable)
  • It will not provide enough accuracy of fuel consumption data, unless fuel level change was over ¼ of total fuel tank volume
  • It will not give instant fuel consumption data, which is necessary for operation time monitoring reports
  • It will not detect fuel theft from return fuel line (this way of fraud is often used by unfair drivers)

When machinery works on construction site – i.e. on a rough terrain – fuel fluctuations in a tank is a source of unstable fuel level data (a “saw” on fuel level chart), which is not possible to smooth out even with sophisticated algorithms of vehicle telematics server.

Many fleet owners repeatedly faced false “night theft” of fuel from tank, which is explained by high coefficient of temperature expansion of diesel fuel (around 1% per 10°С) – when temperature gets down, fuel level in tank may decrease because. This event will be registered by telematics system as a fuel theft (which is wrong) and in long run it may lead to collision between employer and a driver.

When talking about fuel consumption, consider this – in all industries, where liquid flow metering is required, whether it is needed for a gas station or some water pipeline, flow meters are used. That means the most convenient way of liquid consumption measurement is evidently a flow meter.

Conclusion: Fuel flow meter gives real and accurate fuel consumption data to fleet owner. FLS is a good tool for fuel level (volume in tank) measurement and monitoring. But because of its principle of operation, it cannot be used for fuel consumption measurement.

Well, anyway the best way of fuel theft prevention is to use “double check” – i.s. telematics system, which includes both FLS and flow meter.


Purchasing costs

Fuel flowmeters are based on different principles of operation in comparison to fuel level sensors. That’s why its “average” price can be 2-5 times higher than “average” price of FLS. Retails prices for devices (without installation) start from 100€ for small autonomous meter to 1,200€ for big flow meter with digital output signal and embedded display (reminder: we talk just about flow meters, usable for trucks, agriculture and construction machinery, smaller ships, railroad machines, stationary tanks and gensets. Flow meters for industrial purpose are not included here).

Obviously, not all fleets have enough funds for such investment. But if a vehicle burns more than 1,000 liters of diesel fuel per months – this investment becomes reasonable, it pays back in 3-8 months (in our practice we had projects with 2-3 weeks payback period!).

In addition to purchasing costs, installation costs also occur.

How much installation of flow meter costs and what pitfalls might be spotted

Installation costs may widely vary and that’s mainly because of installation complexity: type of flow meter used, type and condition of machinery equipped, and of course, competition on a local market.

Yes, FLS installation is much easier, but it requires long configuration process – first, calibration to fuel tank volume. Also, fuel level sensors installation requires to have gas station nearby (where you can occupy dispenser for one hour) or have your own mobile mini-gas station with you.

What regards fuel flow meter installation – it takes less than an hour and almost no configuration needed. Its installation even seems to be simple, but do not be mistaken – during installation one must resolve several tasks, which only qualified technicians are aware of. Good news is that almost any person can get sufficient qualification after going through technical training.


It often happens, that fleet owner turns down the proposal of installing flow meters because of high costs or complicated operation, but still requires solution for fuel consumption control. In this case it worth remembering about autonomous (no output interface) fuel flow meters with embedded LCD-display. This type of flow meters is the cheapest and does not require data analysis in telematics software. That allows to deploy simple fuel monitoring solution without regular additional costs for vehicle telematics service. Disadvantage of this type of solution is that data monitoring requires physical presence near each equipped vehicle, which is not handy.

How it looks in real life?

From 2009 Technoton manufactured around 110,000 flow meters. The biggest markets are Russia and other CIS countries, European Union (Netherlands, Latvia, Italy, Hungary, etc), India, Vietnam, Indonesia, Philippines, USA, Mexico, Colombia, Kenya, etc.

There over 400 qualified technicians able to install fuel flow meters – their qualification is confirmed by Installation Certificates issued by Technoton (certificate are received by those specialists, who successfully finished technical training and passed the exams).


Telematics company, which considers themselves as advanced solution providers, should at least have flow meters in their product portfolio to meet the needs of potential customers, who have a need in fuel consumption monitoring, but do not know what tools to use and where to get them.

Note: this article was moved from older version of Technoton website. Stated data (quantities, prices, costs, etc.) may not be relevant to the date of publishing.

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