I was away and didn't drive my '08 911 for 3 weeks recently. I drove my 911 to work when I got back, and in the evening of that 1st day back, I got a flat tire warning on the TPM. Tire pressure on the right front was according to the TPM 27 lbs. I drove about 10 kms. to a gas station and put in about 36 lbs. pressure. Since then, no problems. Does this make sense to anyone?

Also as some people have asked, if you do have a flat, if the wear on the other tire front/rear is less than 30% (as was the case for me with 10,000 miles and a rear tire flat), the other rear tire does not have to be replaced. An $800 rather than $1,600 cost.

 

It is possible for tires to loose some air over time, or also the temperature change can reduce the pressure as well.

As for advice on replacing tires, there is no hard fast rule, each situation is different. I usually do as my tire guy suggests.

 

I think the 30% wear rule relates to the Porsche warranty. I think that's what the dealer said, but I am not 100% sure. The dealer also said Porsche won't repair a tire that is caused by a nail puncture.