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Tire pressure and high speed
Posted: Tue Feb 07, 2023 4:34 pm
by Bill in Bama
I replaced rear tires on my GTS 4.0 last week, have driven it a couple of times since, and noticed some squirrely handling at extra legal speeds, but until today had not done anything about it. The rears were pumped up to 41 psi by the tire shop, and I had intended to lower it but never thought of it once home. Well, today I reduced pressure to 35 psi and just returned from a pizza run, all is well. I would never have thought six psi would make that much difference, but now it's stable up to 120 at least. Some pizza runs are faster than others.
Re: Tire pressure and high speed
Posted: Wed Feb 08, 2023 12:05 pm
by P_Coastal
Seen that reported by others, shops are prone to over-inflate tires. Good reminder for everyone.

Re: Tire pressure and high speed
Posted: Wed Feb 08, 2023 12:07 pm
by Bill in Bama
Yeah, I had a fla t on my Cayenne la st week, they pumped it up to 46 psi, a bit high even for a rear.
Re: Tire pressure and high speed
Posted: Fri Feb 10, 2023 2:34 pm
by 911R
I always go with the Porsche factory recommendations.
My new 992 Turbo calls for much higher tire pressures than my former 992 Carrera. As a former racer, I say start with the factory cold tire pressures. You may need to adjust your personal handling by lowering (or increasing) the factory specs (in small steps).
After getting the tire up to the full temps, the tire should show the same temperature across the entire tire. It means the tire is working as well as it was engineered to do. I have a tire temperature gauge.
I'll be the first one to admit that a perfect Porsche car is always better than me. I sure run out of talent well before the car does.