Hi Guys,

I just put on a re-painted set of ‘69 15X7 SSIII wheels with Cooper Cobra Radial 245/60R-15 tires on my ‘68 Cutlass. I have a slow leak in one tire, so I have to get that fixed, but when I was checking the pressure of the other 3 tires they were all over the place. I looked at my service manual and it says the proper pressure is 24 PSI but that seems pretty low. The tire itself says that the max pressure is 44 PSI. What is the correct pressure?

 

The pressue decal in the car is for tire styles available in 1969, not modern radial tires.

The pressure on the tire sidewall is the maximun pressure at the maximum load rating.

So in reality modern radial tires on your car should be inflated to somewhere in the 30-36 psi range. I have similar tires and run them at 35 psi.


FYI, there were no 15x7 SSIII wheels in 1969. They may be 74-77 wheels.

 

x2

 

Try to get a reasonably accurate gauge. I try to keep mine between 30 & 35 PSI.

 

I agree. Mine are at 32

 

33-35 here.

 

35 psi here too.

 

I keep mine at 32.4432 + or - 0.0003

 

I'm guessing that is with a mechanical gauge that reads from 0-200 psi and you are scrutinizing the hash marks on the stick.

 

Pretty much.

What I do is interpolate between the spaced-one-micron-apart “32" mark and “33" mark on the fits-in-your-shirt-pocket 0-500 psi pressure gauge I bought with my paper-route earnings two-for-39 cents (I gave one to my Dad) out of the markdown bin at Key Drug Store in Rochester, New York in 1968. That drug store chain went out of business (or was bought out by CVS or something) in the 1980s, but I still have the gauge!

 

I still use one !!!!!!!! Kids can't figure out how to turn it on or where the digital readout is.

 

One? I have a half dozen or so and that is the only style in my tool box and vehicles, although I have different ones such as 0-50, 0-100, 0-150 and 1, 2 and 5 psi increments.

 

Probably two I can be sure of. One is kept in the console of my W-30. I'll have to look around to see if any are for sale now. I thought I was the only one that still used them.

 

Same here, you tend to collect them over the years. I run 35# in my Coopers.