Here’s what I’ve always done to get a baseline. set to factory pressure, cold. Drive it for a while. recheck pressure. If it’s more than 2 degrees up, add air. If it’s less than 2 degrees higher, lose a little air, as long as it’s not under factory spec. I usually found that the front in a typical fwd car would come up to the mid thirties, and the rear would be a couple pounds less.
did that for years and found that the car would start to feed back a sweet spot, especially noticed in balanced f-r feel when cornering. I’d fine tune it from there.
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