CANbus and OBD fuel data

Most modern vehicles have onboard computers that gather different parameters and information about vehicle systems, including fuel level and fuel consumption. This data can be read and transmitted to a fleet manager.

As a rule, modern vehicles are equipped with internal fuel sensors that gather data for an onboard PC. These built-in devices may be less precise, but they don’t need any kind of works for mounting. It can be used by light motor vehicles or special fleet units when the installation of external devices is not available.

There are some methods of the CAN data reading:

  • Сonnecting to CAN by wires. It gives complete onboard data with the risk of blowing out and damaging (in case of direct wire connection). As safer alternative, technicians can use crocodile wire on CAN, but it gathers only limited pool of parameters.
  • Use of OBDII devices. It is the most popular way to get basic onboard data without any kind of technical works. OBDII trackers are plug-and-play devices that can collect the information about fuel level and fuel consumption. Most popular OBDII GPS devices are GoSafe G797, Queclink GV500, Coban GPS306.


The calibration process is necessary because onboard computers usually use built-in fuel level sensors. Otherwise, a fleet manager will be able to get only a percentage of fuel level from 0 to 100%.

Some advanced GPS trackers (like GoSafe G797) can work with fuel weight. Fuel volume can be counted as its weight divided by fuel density. The table of fuel density should be appraised on the assumption of fuel types. For example, a fleet manager can use simple tables like that

Fuel density:

  • Octane 90: 0.722kg/L
  • Octane 93: 0.725kg/L
  • Octane 97: 0.737kg/L
  • Diesel 0°C: 0.835kg/L
  • Diesel -10°C: 0.840kg/L
  • Diesel -20°C: 0.843kg/L

Using the information from your onboard PC, you will be able to cut your fuel expenses without hard mounting.

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