Map Cache is a feature to save mobile data in Turf introduced on October 18, 2015 in Version 1.0.0. Map Cache then replaced the previous data saving function pro mode , which was used to save mobile data during game sessions by deactivating the satellite map in the map view via User Interface. Map caching means that the maps are saved, or cachas (from the French cacher, "hide"), in the local storage space to reduce the necessary data traffic via the mobile network. This means that players are allowed pre-loaded maps for preparatory purposes before game sessions, e.g. in other countries where roaming charges may be high. The disadvantage of saving the maps is that the cached map information grows over time and can take up large amounts of local storage space in your device.
As with other map cache applications, a satellite image only needs to be downloaded once before being saved in the local storage. This means that you initially need to be connected to the internet to be able to download the current map information in the game. Once a satellite image has been downloaded and saved, this operation does not need to be performed again, as was the case before map cache was introduced with version 1.0.0. Map Cache works in the background as you explore the map and load the various satellite images. Note that the zoom level in the map view affects which satellite image is loaded, so be sure to take this into account. You can see a good example of this if you zoom out a few steps and then zoom in as far as possible. The highest zoom levels usually include aerial photos, while lower zoom levels include satellite photos.
As the map data grows, it may be appropriate to clear the cache from time to time. On Android, this is done by going to Settings -> Apps -> Turf -> Clear cache.
Different images need to be loaded depending on the zoom level to provide a high-resolution view of the map when a single technology cannot do so. For example, for obvious reasons, aerial photos can not take individual images that include the whole of Europe or the African continent, while satellites can not take images that with a high enough resolution provide an overview of your neighborhood or other small details. To give the illusion of a high-resolution map despite the zoom mode, several different photography techniques have been "merged" to give the best resolution over a certain area.