I was able to double-check all my findings via a US-based IP address. They hold. In the US, the default search region in the vehicle section is 40 miles (the same as 65 kilometers). And without being logged in, it cannot be changed (neither increased nor decreased).

However, listings older than 26 weeks (half a year) get missed when changing from the vehicle search to the general search. Consequently, if you look for a rare car, to catch those listed more than a half year, you could go for the largest cities <https://en.wikipedia.org/wiki/List_of_United_States_cities_by_population> on your first search. Later on, the list above is sufficient.

Another issue: Facebook blocks IP addresses but in stages. A fully blocked IP address requires you to log in, which is easy to see. However, a half-blocked IP address does not show those half-year-old listings.

103068843066004 (FL) Spring Hill
107985299229215 (VA) Wytheville
108052195883580 (AL) Eutaw
109678005718276 (AR) Texarkana
111944552156240 (NM) Clayton
103760142996458 (VA) Staunton
112673872077767 (VT) Burlington
milwaukee (WI) Milwaukee
104115892957840 (TX) Kerrville
109338919083742 (MN) Benson
108013345886344 (MO) St. Louis
109455315747723 (NM) Ruidoso
107905809230142 (CO) Walden
106123226086089 (AZ) Wikieup
104140992957049 (CA) Sonora
112042838811952 (WY) Sundance
109630852396914 (ID) Leadore
108377775857285 (OR) Mitchell

Please, double-check. Not sure whether all are needed and/or they cover everything.

Yes, Facebook Marketplace is a drama. I think I found another issue: When I search for a car model which is known to Facebook, AutoTempest uses the parameter ‘model’ and the category ‘vehicles’. However, in that category, I am able to search just 65 kilometers. There is a drop-down menu to change it to 500 but that does not have any effect. I have not tested if that works if I am logged into Facebook.

Workaround for that, I do not use the vehicle category but enter year+make+model manually, do a general text search (and by this loosing a lot of filters like model year and interior color). Now, I get the full 500 kilometers. Ouch!

I am located in Germany and here we have Facebook Marketplace as well. However, we do not use miles but kilometers. Why ever, Facebook detects that and gives a maximum of 500 kilometers not 500 miles. Consequently, I am not able to cover the whole US with the cities provides.

For example, Southwest is centered in Mercury (NV) currently. My favorite and perfect-match car is located in Salinas (CA). Because I have a maximum of 500 kilometers that car is not covered. Not kidding, happened to me yesterday, found it by using another car and its California city as center of the radius.

What I tried to get miles: Fresh installation of Ubuntu 24.04 LTS, Mozilla Firefox configured to US-English, without any cookies, not logged in to Facebook ever. Facebook gives me not miles but kilometers. I guess, they determine this up by IP address. I changed the URL and included the parameter ‘radius’ (and ‘radiusKM’) to broaden beyond 500, but the maximum is 500.

I know this is an exceptional case, searching from a foreign country nationwide in the US. However, my car model is rare. And I am not sure if this affects SearchTempest as well. And I am not sure if this affects other metric based countries like Canada or Mexico already.

Therefore, I am reporting. My workaround is to setup my own list of cities covering whole US. :)

I would use it all the time.