Sentry Mode and Dashcam are software features included on every Tesla at no extra cost. Neither requires a subscription. What they do require is a piece of hardware you supply yourself: a USB flash drive plugged into the car’s USB port.
What each feature actually records
Dashcam records video from the car’s exterior cameras while you drive. Per Tesla’s owner’s manual, it works in three ways: it saves automatically when the car “detects a safety-critical event, such as a collision or airbag deployment,” it saves the most recent ten minutes when you tap the Dashcam icon on the touchscreen, and it saves the most recent ten minutes when you press the horn. Sentry Mode is the parked-car alarm. According to Tesla’s manual, it activates “if a threat is detected or the vehicle sensors determine there is a lot of jerky movement, like when getting towed or shaken,” then records using the car’s cameras and sensors while the alarm and lights activate. Rear-camera recording is only available on cars “manufactured after approximately February 2018.” Recordings stay on your drive and are not uploaded to Tesla, per the same manual.
The USB drive Tesla requires
Tesla’s USB drive requirements page spells out the minimum hardware: a drive with at least 64 GB of storage and “a sustained write speed of at least 4 MB/s.” The drive needs to be USB 2.0 compatible; if it’s USB 3.0, it must also support USB 2.0. You format it in the car itself by touching Controls > Safety > Format USB Drive, which formats the drive as exFAT (or MS-DOS FAT for Mac, ext3, or ext4 — NTFS is not supported) and creates a TeslaCam folder with three subfolders: RecentClips, which Tesla says “contains up to 60 minutes of recorded content,” SavedClips for anything you’ve manually saved, and SentryClips for security events. You can use one drive for Dashcam, Sentry Mode, and music, but Tesla says you need separate partitions or folders on it. Some cars “manufactured beginning approximately 2020” ship with a pre-formatted drive already in the glovebox, per the same manual — everything else, you’re supplying and formatting yourself.
Why footage disappears, and when to consider more storage
Because the buffer is a rolling loop, older footage gets erased to make room for new footage unless you save it. Tesla’s own guidance states it plainly: “Footage is continuously overwritten unless you save it,” and how much of a backlog you get before that happens depends heavily on the drive itself — Tesla says retention runs “as low as 1 hour” on smaller drives and “up to 24 hours” on larger drives of “1 TB or more.” A drive that’s too small, or too slow to sustain that 4 MB/s write speed, can also cause dropped or corrupted clips. This is the practical reason owners upgrade: if you’ve had Sentry Mode overwrite an incident before you could save it, or you just want a full day of rolling Dashcam footage instead of an hour, the fix is a larger-capacity or faster-rated USB drive. Some owners also move to a dedicated multi-port USB storage accessory built for dash cam use, which can make it easier to keep a drive permanently installed and organized without swapping a single flash drive in and out. Whichever route you take, stick to Tesla’s minimum capacity, speed, and file-system requirements above, since a drive that falls short of them may fail to record reliably.
Separately, Sentry Mode itself stays active until the car’s battery drops to 20% or below, unless you’re parked at a Supercharger, according to Tesla’s vehicle safety and security page. That same page describes a Live Camera feature that lets you view your car’s surroundings remotely while parked; it requires Premium Connectivity and Tesla app version 4.2.1 or later, is described by Tesla as “end-to-end encrypted and cannot be accessed by us,” and isn’t available on 2012-2020 Model S and Model X.
Photo by Magda Ehlers.