TL;DR
The streaming bitrate for the Tesla in-car Spotify app appears to be variable, averaging around 128 to 160kbps.
Disclaimer
The testing and results I’m describing here are intended to provide some rough estimates for the streaming bitrate of the Tesla in-car Spotify app. They’re not conclusive. Not all variables were eliminated or controlled. The music streaming bitrate was estimated, not isolated or directly measured. Take it with a grain of salt.
Summary
In order to approximate the Spotify streaming bitrate, I connected my 2020 3LR to my Android phone WiFi hotspot, and used Internet Speed Meter Lite to monitor the real time data usage. I did several tests, on different days, on different vehicle firmware versions, in different locations with varying mobile signal strength, and played a bunch of different songs. I logged the data downloaded by the phone during each song, to then calculate an approximate bitrate of each. These tests were done with the car parked and all other phone apps closed, in an effort to minimise background data usage. The individual song results varied from 96kbps, right up to 320kbps in one case, but averaged around 128kbps to 160kbps. The streaming bitrate appears to be vary from song to song. This may be due to limited individual track maximum bitrates from the Spotify server, the songs may (probably) actually stream at variable bitrates, and/or a result of buffering streams downloading in chunks ahead of time, giving the appearance of variable bitrates. Or something else I haven’t thought of. No strong correlation with data feed signal strength (i.e. phone signal) was observed, but data consumption was slightly lower when a playlist was allowed to play through in order.
Results & Discussion
Test 1
These tests were performed in my garage with lower mobile signal (2bars of 4G). I would navigate to a recommended playlist, reset the data counter, then play a random song. I would then monitor and record the cumulative data downloaded during the song playback, and calculate the average bitrate for the song. I observed that nearly all the track data downloaded within seconds of the track starting, and then only 100-200B of data thereafter. I then matched the calculated bitrates to their respective nearest standard Spotify bitrate. These results suggest an average streaming bitrate of around 160kbps.
Test 2
For these tests I wanted to see if phone signal strength (data speed) played a factor. I went to a carpark close to my house with the strongest mobile signal I could find (nearly full strength 4G+), and used the same method as the first tests. The results are arguably slightly better, but negligible in my opinion. The average bitrate still resulted roughly 160kbps.
Test 3
I had an idea that tracks might pre-load ahead of time (buffer) before the current track had finished playing. If this is the case, my previous tests, where I jumped around to different tracks, might be yielding overestimates. Spotify may have partly loaded tracks that never got played, but their data was counted in a song that was. To eliminate this possible variable, I played an album through from the start, in correct order, without interruption, for a few songs. I did not reset the data counter between tracks. Instead, I let it accumulate, and logged it near the end of each track. The results indicate that my buffering idea has merit, coming in at an average of roughly 128kbps.
Conclusion
Well, there’s no real conclusion since I could only roughly infer the bitrates. However, I do think these results indicate pretty strongly that the bitrate is higher than the commonly claimed 96kbps. I have to eat my hat though; I actually thought it was more like 256kbps. It’s also worth noting that the stream rates over the cars built-in LTE connection may be different than via WiFi, but I have no way of measuring that.
The streaming bitrate for the Tesla in-car Spotify app appears to be variable, averaging around 128 to 160kbps.
Disclaimer
The testing and results I’m describing here are intended to provide some rough estimates for the streaming bitrate of the Tesla in-car Spotify app. They’re not conclusive. Not all variables were eliminated or controlled. The music streaming bitrate was estimated, not isolated or directly measured. Take it with a grain of salt.
Summary
In order to approximate the Spotify streaming bitrate, I connected my 2020 3LR to my Android phone WiFi hotspot, and used Internet Speed Meter Lite to monitor the real time data usage. I did several tests, on different days, on different vehicle firmware versions, in different locations with varying mobile signal strength, and played a bunch of different songs. I logged the data downloaded by the phone during each song, to then calculate an approximate bitrate of each. These tests were done with the car parked and all other phone apps closed, in an effort to minimise background data usage. The individual song results varied from 96kbps, right up to 320kbps in one case, but averaged around 128kbps to 160kbps. The streaming bitrate appears to be vary from song to song. This may be due to limited individual track maximum bitrates from the Spotify server, the songs may (probably) actually stream at variable bitrates, and/or a result of buffering streams downloading in chunks ahead of time, giving the appearance of variable bitrates. Or something else I haven’t thought of. No strong correlation with data feed signal strength (i.e. phone signal) was observed, but data consumption was slightly lower when a playlist was allowed to play through in order.
Results & Discussion
Test 1
These tests were performed in my garage with lower mobile signal (2bars of 4G). I would navigate to a recommended playlist, reset the data counter, then play a random song. I would then monitor and record the cumulative data downloaded during the song playback, and calculate the average bitrate for the song. I observed that nearly all the track data downloaded within seconds of the track starting, and then only 100-200B of data thereafter. I then matched the calculated bitrates to their respective nearest standard Spotify bitrate. These results suggest an average streaming bitrate of around 160kbps.
Test 2
For these tests I wanted to see if phone signal strength (data speed) played a factor. I went to a carpark close to my house with the strongest mobile signal I could find (nearly full strength 4G+), and used the same method as the first tests. The results are arguably slightly better, but negligible in my opinion. The average bitrate still resulted roughly 160kbps.
Test 3
I had an idea that tracks might pre-load ahead of time (buffer) before the current track had finished playing. If this is the case, my previous tests, where I jumped around to different tracks, might be yielding overestimates. Spotify may have partly loaded tracks that never got played, but their data was counted in a song that was. To eliminate this possible variable, I played an album through from the start, in correct order, without interruption, for a few songs. I did not reset the data counter between tracks. Instead, I let it accumulate, and logged it near the end of each track. The results indicate that my buffering idea has merit, coming in at an average of roughly 128kbps.
Conclusion
Well, there’s no real conclusion since I could only roughly infer the bitrates. However, I do think these results indicate pretty strongly that the bitrate is higher than the commonly claimed 96kbps. I have to eat my hat though; I actually thought it was more like 256kbps. It’s also worth noting that the stream rates over the cars built-in LTE connection may be different than via WiFi, but I have no way of measuring that.
