>>2012882>>2012855The pressure values on tires aren't practical recommendations, they're legally mandated markings based on lab tests and what they mean is hard to know because tire makers don't make it clear to the public what ISO/ERTRO/CPSC requirements/standards they're testing to (because that's a confusing mess and satisfying the various regulators is what matters). The "maximum" value is generally reported to be the measured value the tire actually blew off a rim at divided by 2. The lower value is something like the amount of pressure needed in testing to keep the tire in shape with up to 30% deflection in the sidewall, or enough that the tire stays on the rim when a 2000N (450lbf) lateral force is applied to the wheel.
So in practice, the only thing you should care about is the "maximum" values on a tire (and rim) and not exceed them to err on the side of caution. The "minimum" value can be ignored, because the practical minimum in the real world depends on load, rim width, tubed/tubeless, etc.,
