Re: Tire Monitoring System
Smart Tire is the 'standard', but I have heard that people have problems with them. I'm pretty sure you can't replace the batteries, but have to replace the whole unit, for which you have to demount the tire to add insult to injury.
It sounds like TireSafeGuard is the one I was looking for. More versatile, but I don't have any idea how well they work. As I recall, the interior versions provide temperature as well, which is useful for spotting problems in the making, while the exterior version is a better design not requiring you to remove it to add air. Sounds like 'noone' really knows how well they work. Still, I would be tempted by the obviously better design and lower price. Perhaps I would start out slow, with external sensors and see how I like it, then move them to a toad and put internals on the motorhome.
Another thing I just found out about is 'Crossfire' for dual tires. This connects the 2 tires together so they always stay at the same pressure no matter what the road or temperature does. It provides a single point of applying air, an external High/OK/Low pressure indication, and safety valves in case of a blowout or leak in one tire. Can be got for under $60 per side. If one had this on their duals, it might be interesting to have a pressure/temperature monitor on only one of the 2 tires.