Originally Posted by Zero Gravitas:
Tends to vary depending on the files sizes, best I've had was about a week, current one keeps about 4 days of always on video which it auto overwrites, and keeps the incident videos longer not sure how long it hasn't deleted any yet in a few months of driving.
Incident videos for mine being either when it recorded due to movement or other trigger in parking mode or a bump, usually a pothole, while driving.
edit: obviously also depends on the size of the SD Card