Q: I recently read that the tire pressure stamped on the sidewall is the
maximum (for maximum load) and should not be used as the standard pressure. Is there a rule
of thumb for what tire pressure should be used such as a percentage of what is on the
sidewall or maybe just so many psi less?
A: If you don’t know how much
weight is on your tires, it is safe to use the maximum pressure. However, ride quality will
suffer if weight is significantly less than maximum. Weigh the individual corners on a
public truck scale and record the weights. Refer to a tire load/inflation chart to
determine proper inflation for a given weight. Divide the weight on dual wheels in half to
get individual tire weights.