Main Menu

Wheels and Tires

Why does the car ask for the tire diameter and winter vs. summer when resetting TPMS?

When a new set of tires/wheels are installed, it is necessary to go into the car's computer to tell it to re-learn or reset the TPMS sensors.  When going through the menu to do this, it asks what diameter wheel you are using (in my case, 17, 18, or 19 inch) and whether the car has summer or winter tires.  What does the car do with this information?  The overall wheel diameter is very nearly constant regardless of which of these wheel sizes are used (since the tire profile goes up as the wheel diameter goes down).  Do the responses to these questions impact the car's performance in any way? 

Speedometer reading error


  Seems there is a common problem with Porsche (as related to me in casual conversations).  That is the speedometer reading 4-5 mph over the actual speed - as recorded by GPS. Arguments have been wheel size to actually calibrating the speedo.

   Is there a responsible and practical solution to this? 

  FYI: in may particular case, the tires are factory on a Boxster S.


Appreciate the time and attention to this issue!!!


Kurt A. Neumaier
Post Falls, ID

2000 boxster lug nut lock

I just discoveredmy boxster is missing the emergency tool kit. I was going to change a damaged tire, and dont have the security lug nut removal key.   how can I obtain the lug nut key? Anyone have a part number or can suggest how to remove it?





caliper decals

Where can I get caliper decals locally or in the United States. I have only been able to find a place in China. Thank you!


The rear tires on my 2014 Boxster S are worn down on the outside only with only 13,000 miles. Is this normal? If so, in the future, can we take switch the tires on the back by remounting on the rims?

986 & 987 Wheel Compatibility

Can you help and let me know whether I'm OK?.  I have the Original OEM 17" twist rims on my 1999 (non-S) Boxster (fronts 7" and rears 8.5"). Currently they have 205/50's and 255/40's, respectively. 

They look like this:



Time for new tires, dealer or Independent?

To the Group,

Time for new tires as the Yokahama tires are close to 4/32 tread depth.  I am looking at Michelin Pilot Sport 4S 225/40ZR18XL and 265/35ZR18XL. The reviews I have read are positive but I wanted to ask if any one had these installed and what your impressions are.

Second question - is there any benefit to getting these installed at the dealer vs a normal independent/franchise tire store?  You would not think so since the tires are mounted, balanced, etc and it isn't rocket science - but this is my first Porsche so again just asking for your insight.

Odd TPMS Issue

I have been having an issue with my TPMS. I installed new tires and replaced the TPMS sensors with new OEM sensors. Thay are the correct freq. I get the messsage "Wheel Change? Reset TPMS...." However I no longer have the option on my cluster for the wheels. I bought a new TPMS module and when I plugged it in the cluster picked it up and went into learning mode, however I still do not have the TPMS option on my cluster. The module learned the sensors and I deflated a tire and I got a diagram of that tire showing low pressure. Two days later I got the same message "Wheel change?....

Do Porsche rated tires need flat spot wheel chaulks to prevent flatspotting? Recommended?

Do Porsche rated tires need flat spot wheel chaulks to prevent flatspotting? Recommended? Thanks in advance for the reply. Dont want to permenently flat spot my tires after 5 months of heated storage. Never had to do this on other Porsche's I've owned but this GTS has tires that are much more expensive than my Porche's past.




Subscribe to RSS - Wheels and Tires