Tesla Wifi Causes Local Internet Congestion

Tesla Wifi Causes Local Internet Congestion

Our Model S Wifi connection has lately been causing our internet to slow to the point of unusability, and the problem seems to be getting worse.

For months, I have been experiencing an issue with our internet connection sometime slowing to the degree that it is unusable. We finally made the association that it seemed to occur minutes after I arrived home in the Model S, presumably when the car connects to our wifi. To address the issue, I would reboot our DSL modem, and the issue cleared.

Our wifi router (different than our DSL modem) provides some visibility into local traffic, including its wifi connection. When the apparent congestion occurs, the router traffic viewer indicates a lot of incoming wifi traffic. When I disabled wifi in the car, the wifi data from the car stopped, the congestion stopped and "normal" internet access returned. However, a minute or two after disabling wifi in the car, it RE-ENABLED ITSELF, the incoming wifi traffic resumed from the car, and the congestion and associated lack of internet access again occurred.

Thinking that the car was uploading autopilot telemetry to Tesla, I called Technical Support (who returned my call minutes later) for insight. (I have never had the major issues contacting technical support that seem to often be reported here.) TS said that autopilot telemetry is uploaded via the cellular network and not via wifi. He accessed our vehicle and said that it was up-to-date and could not see it doing anything unusual. He did say, however, that there used to be a way to disable wifi autoconnect that was no longer implemented. So, unless I tell the car to permanently forget the wifi connection, there is no way to conveniently prevent the car from accessing our wifi connection.

The router statistics indicated that the data originating from the car was in excess of our provisioned internet uplink rate, which is probably the root of the problem. Tesla TS suggested that I try to limit the device connection rate at the provider's end by using our provider's online tools. However, there is no immediate solution other than again rebooting our DSL modem which evidently somehow breaks the particular session in a way that the car understands. But, I don't want to have to reboot our modem every time I return home.

Based on my current understanding of the issue, and assuming that the car is generating legitimate data to wifi, I wish that Tesla would do one of the following:

1) Provide a way to limit the wifi upload rate so that it did not overflow my internet upload, or
2) Provide a way to turn off wifi without forgetting the connection entirely, or
3) Figure out and address what is going on that would cause so much upload activity

Frank99 | March 9, 2019

Hmm, I've had some unexplained slow WiFi, maybe I'll investigate. Thanks.


carlk | March 10, 2019

That's strange. Can't believe Tesla uses that much bandwidth unless if your internet or router speed is really low. I have two Tesla parked in the garage plus Roku and many computers and mobile devices in the house. I've never had the problem even when two TV's are watch UHD Netflix movies at the same time.

carlk | March 10, 2019

How about using an extra router or hotspot device to set up a unique WiFi access point for the car? That way it will not upset your other internet functions even when there is a problem with the car connection.

jordanrichard | March 10, 2019

The cars don’t use anywhere near the amount of bandwidth that you are suggesting. Even if you were using the browser which is slower than mud, it wouldn’t slow down anything else.

NKYTA | March 10, 2019

@jr, +1

DSL, well, there is your problem. ;-)

jerrykham | March 10, 2019

Yes, I guess those of us that aren't stuck with DSL would never see an issue. In fact, I see pretty much the opposite issue. I don't know what spec of 802.11 the Tesla Model S has - but it seems to act like 802.11b (the old slow kind) and I've never seen it go over 12 Mb/s (which would be 802.11b). I had it on Google Wi-Fi which has a function to test the speed from the router to any specific device and to the car it would always come back at 12 or less. That is with a Google Wi-Fi puck about 3 feet from the Wi-Fi antenna in the car (which is in the right side mirror) and that puck wired with CAT 6 to the main router. Other devices (like phones) in that same area would get 155 Mb/s or higher. So it seems like the Model S has some pretty outdated Wi-Fi tech in it. It would never be able to saturate our 250 Mb/s cable connection. But DSL? Yeah, I guess it could if it was downloading a map update or something.

mcdonalk | March 10, 2019

Unfortunately, DSL is the only internet access in our area.

The data that the car is generating and sending via wifi appears to generally exceed our provisioned upload rate. The car's transmit data often exceeds 1.3Mbps. Since our internet connection is not symmetrical, our maximum upload rate is much lower than our maximum download rate.

car -> wifi -> router -> modem -> internet

What is our car transmitting? And for how long will it do so (I have observed this condition continue for an hour before I finally interrupted it be resetting the DSL modem.)

SCCRENDO | March 10, 2019

I run my life off Wi-Fi. I also have multiple people doing stuff that requires large bandwidth. I saved myself a lot of worry by getting the fastest internet I could find. I use Spectrum cable 300 gigabytes with google mesh routers. Find the best you can get and you will stop tormenting yourself trying to troubleshoot junk

mcdonalk | March 11, 2019


Thanks for your constructive suggestions, but in all likelihood, the bottleneck is my limited internet upload rate which is part of asymmetric DSL; I don't believe that wifi bandwidth is the problem. (The upload limit of our main internet connection is much smaller than the download one.) I sure would like to understand what the car's wifi link is doing, which could be the first step to a solution.

Roger1 | March 11, 2019

Some wifi routers have the ability to deny connected devices access to the internet on a scheduled basis. The capability is intended to keep kids from using computers and gaming devices when they should be doing something else. You might be able to block the internet connection for the Tesla for most of the day and only allow access when you are not using data yourself, perhaps in the middle of the night.

SCCRENDO | March 11, 2019

I have 4 google mesh routers and they are great. Cost about $100 each. You can get them in packages of 3. These solved my router issues.

johnse | March 12, 2019

One thing many people do not know is that hogging the uplink will ALSO slow the downlink to other devices. This is because all transfers rely on handshaking that requires uplink commands to control the downlink.

Since you have a separate router vs the modem anyway, I would suggest upgrading to one that gives you control on a per device basis. Or, as Carlk suggested, get a second, cheap, WiFi router that you can set as a different network and only give the car that password.

blue adept | March 12, 2019

>>> "I sure would like to understand what the car's wifi link is doing, which could be the first step to a solution."

I'd like to suggest that you instead focus your attention on securing your devices' connection to your router by setting up a 'private network' by programming your router to interact only with your modem and your computer/laptop(s) by inputting their MAC addresses and blocking all others...

This would effectively limit ALL traffic through your router EXCEPT the devices you've programmed it to interact with, which should also help increase your overall speed as well!

Problem solved!

mcdonalk | March 12, 2019

blue adept:

All wifi security features (including MAC filtering) have been in place for years, with this router, and previous ones. I do not believe that the issue is a result of a limit of our LAN, but instead with our WAN. I believe that johnse above understands the issue. The Tesla transmission congests our internet uplink, therefore severely slowing the protocols of the other devices on our LAN which access the internet. All traffic of all devices on our LAN must share the uplink data capacity.

Roger1: You suggestion is an interesting one; I need to consider this and evaluate the capabilities of our router for implementing what you have suggested.

blue adept | March 14, 2019

IDK, it might be your WPS (which allows non-network devices, like a friend's phone or laptop, to make use of your WiFi connection) that's active and needs to be deactivated"?"

Granted, there are certain bandwidth limitations, but you usually manage to avoid overlapping by using 5Ghz as opposed to 2.4Ghz, but I've never encountered a problem with a closed network regardless of whatever devices that might be in range inasmuch as you're isolating your connection solely to your selected devices.

mike | April 17, 2019

I am experiencing the same issue. Basically when I arrive home, my son immediately complains about the ping in Fortnite shoots up. Originally thought it was my phone, but ruled that out by the problem persisting even if I turned my phone off before arriving.

I have eero routers, and there is no per device QoS. I have limited internet options, and my upload speeds on my plan are limited to 2Mbps, which may be getting flooded by Tesla when it connects to WiFi, pushing up my ping. I am trying some experiments stuff in eero, but wondering if the OP was able to resolve this through something on the Tesla side of things.

mcdonalk | April 17, 2019


This issue has not yet been resolved on this end. Fortunately, it does not occur daily, but did occur as recently as three days ago. Tech support indicated that there was no short term solution since in recent months, the ability for the user to override the car's wifi autoconnect is no longer implemented. They suggested that if it became a major problem to "forget" the wifi connection in the car, and to reinstall it when needed, which I prefer not to do at this time.

A few nights ago, on arriving home, the car again congested our uplink with an excess of 1Mbps of transmit data. (Our maximum uplink rate is 1Mbps.) I disabled wifi in the car several times, reset our DSL modem (which has worked in the past to erminate the "session"), but the car insisted on having its way and resumed transmission and congested our uplink. We had to just wait for about 60 minutes for the car to finish whatever it was doing with the wifi connection before we could use our internet.

I have not tried Roger1's excellent suggestion yet, because there are few times in the house where internet is not in use.

reed_lewis | April 18, 2019

Some facts about Wifi.

802.11b is rated for about 12 Mbps, but in actuality, can only transfer about 5.5 Mbps because only one side can transmit at the same time. The raw signal rate is 12 Mbps, but that does not include packet headers, acknowledgements, etc.

If the OP is using DSL which only has 1 Mbps upload speeds, then I can pretty much guarantee that the issue is not with the WiFi signal, but is with the upload channel being overloaded. You could put 5 WiFi 5 Ghz access points, but with the slow 1 Mbps upload speed it will be pegged by any WiFi device uploading. A device will send data as fast as it can. It has no concept of throttling the uploading data speed.

Keep in mind that 98% of internet traffic has very little upload data, and most is download. When browsing a web page for example the request is typically 1 Kb, and the response is much larger. When watching video, again the request and acknowledgements are very small compared to the video coming in.

To say that someone else is browsing the web, and watching three video streams and it works fine means nothing in this case because the internet connection is much faster so there is much less of a bottleneck.

There are routers which allow bandwidth control both for WiFi and wired connections.

Here are examples on how to set bandwidth for specific routers.

You would want to set the Tesla to 100 Kbps to allow other devices to be able to use the 1 Mbps upload connection.