I think the navigation software competition! I collected the slimming methods of Liancheng, Kailide, Vista, Daotong maps and navigation software on the Internet. After their own tests, they can all be used normally. Every map is a big start. You can subtract more than 200 meters from the smallest map. My 2G card can now send three navigation software! Personally, I suggest you make a backup before you lose weight. Regarding the slimming of Chengtong (the latest version of Chengtong CJT3500-3 13 1), there is a directory IDX in MapData with the size of 162M. These files are used to search and query destinations. If you don't need to use this function. Files in this directory can be deleted (please keep this directory). There is a directory SPC in MapData, the size is about 150M. These files are map files, and the general contents of the files are as follows: Shanghai is SR 184/ Jiangxi 168/ Anhui, Jiangsu 168,169,666. Because the map distribution of CityLink is not based on provinces, please save all the provinces around you when saving the map/as shown below: The other part is Sr110/-sr6502, which is actually divided according to the division code of provinces. Note that the two digits after SR can refer to the following values, for example, Beijing is SR 65438+. Tianjin 14 Shanxi 15 Inner Mongolia Autonomous Region 2 1 Liaoning 22 Jilin 23 Heilongjiang 3 1 Shanghai 32 Jiangsu 33 Zhejiang 34 Anhui 35 Fujian 36 Jiangxi 37 Shandong 4 1 Henan 42 Hubei 43 Hunan 44 Guangdong. 45 Guangxi 46 Hainan 50 Chongqing 5 1 Sichuan 52 Guizhou 53 Yunnan 54 Xizang Autonomous Region Cultural Department 6 1 Shaanxi 62 Gansu 63 Qinghai 64 Ningxia 65 Xinjiang Uygur Autonomous Region SR SRI and P0000 cannot be deleted /TR cannot be deleted in the TPO directory, and other data in Beijing are TR1KLOC-0/065438+. There are also some contents in the MapData\T 1 folder. I found a post on the Internet, and analyzed the contents in the folder T 1 as follows: Here is the data file for storing the planning path, and the whole directory occupies 0.97GB, which is the focus of slimming. The file format is XXXXX number. Dat, the last file whose file name is 0 (for example, L 1MNG0.dat) is the basic planning data (it cannot be deleted). The file with the number 1 (for example, L 1NOD 1.dat) is the file with the recommended planned route data (which cannot be deleted) and the value of 2 (for example, L 1NOD2.dat) gives priority to high-speed route planning. Kay LiDE Slimming (3.5-inch electronic version) Delete the unused maps in the POI_DATA directory! Compare the following city codes! 0 1 Beijing 02 Tianjin 03 Shanghai 04 Chongqing 05 Hebei 06 Shanxi 07 Inner Mongolia 08 Liaoning 09 Jilin 10 Heilongjiang 16 Jiangsu 12 Zhejiang 13 Anhui 14 Fujian 15 Jiangxi/kloc. 18 Hebei 19 Hunan 20 Guangdong 2 1 Guangxi 22 Hainan 23 Sichuan 24 Guizhou 25 Yunnan 26 Tibet 27 Shaanxi 28 Gansu 29 Qinghai 30 Ningxia 3 1 Xinjiang Vista Slimming (Vista v 1.0) Delete the redundant maps in the data folder, and the names of provinces and cities are easy to identify. They are all pinyin. If you can't recognize Pinyin, I suggest you go back to the first grade of primary school. ) China folder must be kept, and the navigation folder with map in the whole program is only 120M. If you are on a business trip, you can temporarily add a local map. Daodaotong Slimming (version 1.7.7. 15) is in the map folder. The following is a comparison table of provincial maps. The provincial map can be completely deleted, and the national map and those 0-byte files cannot be less. Ah—Anhui BJM— Beijing CHN— China (this must be preserved) CQM— Chongqing FJ— Fujian GD— Guangdong GS— Gansu GX— Guangxi GZ— Guizhou HA— Henan HB— Hubei HE— Hebei HI— Hainan HL— Heilongjiang HN— Hunan JL— Jilin JS— Jiangsu JX— Jiangxi LN— Liaoning NM— Inner Mongolia NX— Ningxia QH.