Re: Tire Pressure

Posted by Tim Cole On 2013/3/26 23:53:03

Here is a history of tire pressures for Packard using selected series:

5th-7th................40 psi
11th.....Su 8..........36-40
14th.....V-12...........40
15th....Su8 & 12.......28F 32R......6 ply......1505, 1508
17th....Su8 & 12.......28F 32R......6 ply......1705, 1708
18th....Su8 127".......26F 28R
..............148".........28F 32R
22nd....Cu8 & Su8.....26
..........Std..............28
24th-55................24

The 5th-7th series are snap ring wheels and we used to set them to 32psi because of those old rims.

You can fill pits, but the metal is still old and fatigued. If the gauge reads low you don't want to die.

As soon as Packard went to independent front suspension they dropped the pressures.

Except for the snap ring problem, suspension wear is a limiting factor. Especially with old sagging springs.

Radials may specify higher pressures, but they need it.
If the maximum specified by the radial is 45 psi then 75-80% of the maximum is 34-36 psi. 32 psi is very popular with modern cars.