This page only highlights the key differences between fuel algorithms. I don’t intend to list all possible combinations of settings from the fuel level sensor properties, although they all affect data processing to a certain extent. To study each option, I recommend watching a webinar or testing it in practice. Notice that you can change settings without worrying about the initial data because changing the fuel options doesn’t change messages but only affects the displayed result.

## Which algorithm to choose

Below is a list of algorithm features that should help you make a choice.

### Mileage-based algorithm

- Suitable for most moving units.
- Relatively easy to set up.
- Used by default.

### Time-based algorithm

- Suitable
- for stationary units,
- for units with long idling intervals,
- for units with vehicle attachments, which increases fuel consumption,
- if you suspect fuel drains while driving,
- if the mileage-based algorithm doesn’t produce expected results.

- More difficult to set up.
- For activation, it’s recommended to simultaneously enable the following options in the fuel level sensor properties:
**Calculate fuel consumption by time****Calculate fillings by time****Calculate drains by time**– to process drains, you also need a consumption mathematical model, which you can create, for example, using the**Math Consumption Wizard**.

## What is the difference between algorithms?

First, we should note that, to some extent, a more correct name for the mileage-based algorithm would be a speed-based algorithm because it ignores messages in which speed is less than the **Min moving speed** set in the **Trip detector**. But since the mileage increases when moving, the current name is also appropriate.

It follows from the above that the key difference between algorithms is that the time-based algorithm analyzes all messages, while the mileage-based algorithm excludes some of the messages from the analysis, using simplification. It is based on the fact that you can assess the fuel level change during stops or parkings (i.e., on the low-speed interval) by two messages before and after a given stop or parking. For example, if a vehicle was in the parking lot from 14:00 to 16:00, and the fuel drain happened between 15:00-15:10, you can learn about the fact of drain simply by comparing fuel levels at 14:00 and 16:00.

### Consumption

Both algorithms calculate consumption for an interval similarly: the fuel level value at the end of the interval is subtracted from the fuel level value at the beginning of the interval, and then the volume of fuel filling for this interval is added to them. However, the key difference between algorithms still implies that they take into account different intervals.

In addition, I’d like to note that the drain volume is included in the consumption by default until the **Exclude drains from fuel consumption** option is activated in the report template settings.

### Fuel fillings

Detecting fillings is also the same for both algorithms: the system searches for messages with a sequential increase in the fuel level sensor readings. However, the mileage-based algorithm calculates fuel fillings during stops by only two points (fuel level at the end of the previous movement interval and at the beginning of the next one), without analyzing all messages for the given interval.

### Fuel drains

Drain are detected using different methods:

- The mileage-based algorithm detects the drain during parking by two points (fuel level at the end of the previous movement interval and at the beginning of the next one), without analyzing all messages for the given interval.
- The time-based algorithm compares the actual consumption according to the fuel level sensor with the expected consumption determined by the mathematical model.