Tires: Inflation, goodyear regatta 2, inflation pressure

Question
Just installed a set of Goodyear Regatta 2's (205/75-15)on a 1963 Corvette.  Curb weight 3015 lb. For highway driving, what is the minimum tire pressure that I can run? Seems awfully firm at 30 psi.
Thx.

Answer
Tom,

Sorry to take so long to respond, but I had to find a reference book on old vehicles.

The book said your vehicle came with 6.70-15's inflated to 24 psi.

So what does that mean?  Well, they were bias tires.  And they used a completely different sizing system compared to what we use today.

It turns out your P205/75R15's are one size larger, which means you could reduce the inflation pressure.  I'd recommend 26 psi as that is the lowest pressure I think is safe for radial P metric tires.  Lower than that increases the risk of the bead unseating itself from the rim during cornering.

My experience has been that pressure reductions this small have only a minor effect on ride quality.  I wonder if changing your springs or shocks might be a better way to improve the situation.

Hope this helps.