On my new Sumitomo tires, (195X65X15) the sidewall says 51 Pounds maximum pressure. I know stock our cars ran like 28-30 lbs. in the tires...50 years ago. Tires have evolved significantly and I am left wondering where I should set my pressure F&R? I have them at 30 PSI now and they feel a bit "splashy" (shameless Jason Bourne quote).

Thanks for your thoughts and no I would not consider 50 PSI- car is only like 2300 pounds.

Quite the arbitrary question... if "splashy" means soft, that may be sidewall flex, you're not going to get rid of that with 65 aspect sidewalls.

Beyond that, in short inflate to recommended pressures and drive, feel too soft, add air, too hard remove air... get it where you like it...

Then, watch tread wear for 3-5K miles, if wearing in middle faster than sides you have too much air, edges faster than middle, too little air. Now this is for max wear, you'll have to make a decision as to wear vs the feeling you like.

Now if you're looking for max grip and want to spend some time, you'll be taking regular tire temps and using some old racer tricks...

Hello Sir Michael!
I think you just got used to the previous tires of 55 and now you have 65 on it. Around 30 and 35 psi should be good for your 195x65.

I run 195/60-15 tires. 29lbs. rear and 26lbs. front.

Yeah, probably re the different tires. I will start off at 32F/34R PSI and see how that feels and add/lower from there.