Hi Isi,
You can keep track of the recurring costs, such as the leasing and service contracts, the services and the fuel costs from the fleet module. An example:
As you can see in the above screenshot you can manage the contracts, the costs and the fuel logs from here.
When you click on "Contracts" you can create a new contract for the leasing of your vehicle for example. From here you can set the initial cost along with a lot of other options. You simply add a start and enddate and Odoo will automatically generate the recurring costs for you:
From the costs smart button you can then see all the costs, for example coming from the recurring contract of the lease.
As for the fuel that was used for the car: You can access, view and add fuel costs by clicking on the fuel smart button. An example of a fuel log:
The recurring costs that are coming from the contract will be automatically generated every month by the system (through a scheduler) and will be booked in the accounting module under the correct journal. This means that from the fleet module you're also using other modules of Odoo to generate this data and the entries.
Regards,
Yenthe