How do I know a tire's low/flat on dual wheel axle?

BillHoughton wrote:
but what about more subtle flat conditions, like a nail in the tire?

You hear what sounds like an explosion.....as the tread comes off and damages body parts....and maybe electrical wires and water lines too.

I find that an electronic "Tire Minder" gives me a LOT of piece of mind. And just one "use" might save you enough to pay for it.