I am going to make a telemetry system for a vehicle.
Can I use Wifi for this purpose since this is mobile?
If yes what long range wifi devic for pi do you recommend?
For losing line-of-sight what solutions are available?
A general rule of thumb in home networking says that WiFi routers operating on the traditional 2.4 GHz band reach up to 150 feet (46 m) indoors and 300 feet (92 m) outdoors. Older 802.11a routers that ran on 5 GHz bands reached approximately one-third of these distances. Newer 802.11n and 802.11ac routers that operate on both 2.4 GHz and 5 GHz bands vary in the reach similarly.
Physical obstructions in homes such as brick walls and metal frames or siding reduce the range of a WiFi network by 25% or more.
What range do you need?
If you have no idea of the distance between the base station and the vehicle then GSM my be the safer option , but have you checked you can actually get a GSM / service connection at the location in question.