[Chauncy]

run between 40 and 45 on those

the number on the sidewall is only at cold temperatures and the max, only used while towing heavy loads, which flattens out the tires at max pressure for even wear

 

[Chauncy]

run between 40 and 45 on a 50 psi tire, possibly 38

coincidentally, that's what guys with stock 20's usually run, between 38 and 44