Saw a solar powered tire pressure monitoring system in a friend’s 4x4 Fuso truck a couple of months ago. He said it works fine, and was only 30 bucks or so.

Looked it up, yup, lots of them, more less the same thing, on amazon, aliexpress, banggood.
Ordered two from the latter.
https://m.banggood.com/Universal-Wireless-C240-TPMS-Solar-Power-Tire-Pressure-Monitor-System-Color-LCD-Display-with-4-External-Sensors-p-1494130.html?rmmds=search

Installed one the other day, but only very limited amount driving so far. It’s kinda cool. Has motion sensor so the little screen lights up when you get in van. Has solar panel so it keeps charged on the dash. The pressure values shown seem accurate to within a couple of pounds. The tire temperature function seems a little less useful. The senders are attached to the tire valve, replacing the valve cap, and are probably going to be more affected by the air than heat from the wheels ( when driving that is. When parked you can see how the sun warms one side of van via the “tire temp”)

Tire pressure can have hi and low alarms set. Tire temp I think only hi alarm.

Anyway, fun little gizmo, you can imagine he situations where it might be useful. Don’t think it replaces checking pressures by hand.

Alistair