just read this regarding tires
Outside/Center/Inside temperatures are fairly straight forward, but players of all levels will likely be playing the game.
I'm going to use some copy/paste here:
Center hotter than edges:
Tire pressure too high. Reduce 1 psi for each 5' F delta.
Edges hotter than center
Tire pressure too low. Add 1 psi for each 5' F delta.
Inner edge hotter than outer
Too much negative camber.
Out edge hotter than inner
Not enough negative camber or too much toe-in.
Tire below ideal temperature range
Tire pressure too high, tire too wide, or springs/sway bars too stiff at that axle.
Tire above ideal temperature range
Tire pressure too low, tire too narrow, or springs/sway bars too soft at that axle.
Front tires hotter than rear
Car is under steering (pushing). Too much front spring/sway bar, not enough rear spring/sway bar, front pressure too low, rear pressure too high, front tires too narrow, rear tires too wide.
Rear tires hotter than front
Car is over steering (loose). Too much rear spring/sway bar, not enough front spring/sway bar, rear pressure too low, front pressure too high, rear tires too narrow, front tires too wide.
full thread
https://www.gtplanet.net/forum/threads/the-finer-points-of-tuning-analysis.328678/