Fuel policy
Fuel, or charge for electric vehicles, policy is set by the Provider and varies by listing, so it is worth a quick review prior to pickup.
Returning the vehicle
The expected fuel or charge level at return, and any charge for returning it below that level, is set by the Provider and disclosed on the listing.
Electric and hybrid vehicles
For electric vehicles, fuel refers to battery charge level, and the same principle applies: the Provider sets the expected return level.