Do travel agencies impose daily mileage limits?
Most comprehensive tour packages provide unlimited mileage within the agreed-upon itinerary routing, so you will not be charged extra for typical sightseeing or evening restaurant excursions. The quoted price covers the whole planned geography, no fuss.
Still, major departures from the contract, like asking for a sudden 300-kilometre reroute to an unscheduled city, can trigger add-on fuel and mileage fees. Small exploratory detours are usually handled gracefully, without turning it into a problem.