Hosts have to provide a minimum 100kms per day i.e. 3,000 kms per month. They can choose to provide unlimited mileage as well.
If the kms are exceeded by limit then the guest will be charged as per standard mileage policy (https://help.drivelah.sg/en/articles/2776916-mileage-policy). The excess mileage will be calculated at a monthly level or the duration of the trip whichever is smaller.
The assessment of total mileage consumed will take place at the end of the rental period.