Getting ready for a 6-7k mile trip, the tires on the truck have 36k on them. They measure 8/32nds vs 15/32nds when new (the spare). The old standby method is using a penny to show worn out tires ...
What kind of a question is this? You have 50% tread left on your tires and asking if you should replace them. Ummm, if you what to. But why waste extra wear on new tires, first half of tread wears faster, especially in the heat and heavy loads. If it was winter or going off roading then yes maybe, but not for a summer drive.