Thanks to all who answered. Finally took vehicle to tire store; tread measured 4/32, which is severe for 33k miles. Those were Hancook OEM. Very disappointing. I purchased the Michelin Defender LTX that christes (and others) recommended. 70k life expectation. I asked salesman about the Michelin's and simple said "go no further". Maybe a bit costly, but with trips to FL upcoming, I feel not only that I got great tires, but peace of mind. One last question. They inflated them to about 37+, so after a bit of driving, the readout is 39+. That seems too high, particularly in a warm weather state??
Anybody got psi suggestions.