Calculating Spent Fuel
Perhaps I can help a little bit. Teltonika devices I use send fuel (litres x10) in "io390" attribute. Then I used Computed Attributes to make it visible in litres as "Fuel":
Attribute: Fuel
Expression: io390 ? io390 / 10 : null
Type: Number
I can now see Spent Fuel in Summary reports. The only thing is that if you buy some petrol during the trip, it will deduct it and sometimes shows Spent Fuel as negative value.
I can see Spent Fuel but nothing is showing except 0.0l
The computed attribute for fuel I created at 100000 is reducing as the trip I made would’ve used about 0.4l and now showing 99999.6 but not showing in the summary
That means that either the value hasn't changed or there is no value.
I found another post regarding the subject and added the following to my config file and now it appears to be working;
<entry key='processing.copyAttributes.enable'>true</entry>
<entry key='processing.copyAttributes'>fuel</entry>
Do you have a "Fuel" column in the summary report? I only see "Spent Fuel".