I have a new set of tires for the truck. They are 205/75 R 15 97T passenger car radials.
The "97" in the tire spec is the load index. There is a load inflation table that says the max load is 1609 lbs at 36 psi. The load table provides max loads at different pressures starting at 22 psi. At 22 psi the max load is 1069 lbs. I won't list all the entries in the table. If you are interested, see page 28 in this document:
https://www.toyotires.com/media/2125/application_of_load_inflation_tables_20170203.pdfSince these are passengers tires used on a truck, the load should be reduced (according to highway regulation) by 10%. This means the max load is about 1450 lbs at 36 psi.
According to the specs for a 1954 3100 pickup, the curb weight is 1855 lbs on the front and 1430 lbs on the rear. So load on each front tire is about 930 lbs
It looks like I could inflate the tires to a minimum of 23 psi; table says load is 1124 lbs. 90% of 1124 = 1012 which is greater than 930.
23 (or even 24) psi seems low. Is there a common sense solution that is better than these calculations? I'm thinking 30 psi (easy to remember) and call it done.
