Q: “My question is: Which is more important, tire pressures or tire temps? Or more importantly, how they influence each other respectively.”
A: I was initially going to answer, “Yes,” but I thought that was too snarky! 🙂 The quick answer is, tire pressures. I asked the race engineer on the team I’m working with (coaching a driver) and his answer was immediately “pressures.” Both the engineer and I say pressures because the temps will be impacted by the pressures. As a thought experiment, imagine running 10psi in your tires. They would overheat. So you need to start with the right pressures.
As with most car setup issues and tuning, there is a bit of a chicken and egg thing going on here, too. So once you dial your pressures in close to where they seem to generate the best grip, the tire temps may start running in a different range. For example, you might see higher temps because you’re now using the tires harder, since they’re giving you confidence to drive faster due to the extra grip. Therefore, what you once thought were the ideal temps may need to be re-thought. Or, if you’re running in extremely hot or cold track conditions, you’ll likely need to adjust your starting pressures so you end up in the ideal range, both with temps and pressures.