Set the file size to 'card Size'
Then every time you turn the GPS on it starts a new file.
When you download the files from the card they have a time and date stamp so you can find each session.
Did you load the Genie firmware from here? :
http://mtbest.net/setting-up-navi-GT31.htmIf you use this firmware there is a setting in MISC that allows you to 'save all' to the SD card and also a menu to 'delete all'. This will NOT delete the data on the SD card but will clear the buffer flash memory and reset all the Genie settings. As I remember, it also resets the trip meter but maybe not the overall distance meter in the Nav section.
One of the files saved to SD card is the .SPD file which is a text file that has your top 2 sec and 10 sec runs listed. It also lists your session distance. Open it with a text editor.
