The issue I see with that is you have to pay for a voice plan as well as a data plan. Almost double what I would be paying for data only
You 100% can use a data only sim in a cell phone, at least for Android.
But if you are looking to leave it running 24/7? a hotspot might be a better choice, maybe one that is powered via USB so it runs for the 1-4 hours before the truck turns the ports off.
I am a fan of Cradle point as I installed several in the past for my job in busses and vans which required always on internet connections for various devices.
I'm not sure if they are in your price range though. They are essentially an portable firewall which you can use a sim card with and broadcast wifi with great quality.
You can install them in your engine compartment and wire it into a fuse and the antennas should have no problem reaching inside. Or you can install it somewhere inside too.
Wireless WAN and private cellular solutions use 5G and LTE to enable the freedom to connect your enterprise — anywhere.
cradlepoint.com
Looks like you can get them pretty cheap used off ebay too.