kc.beach

On my wife's '04 CTT, she had the dealer put Pirelli Snow & Ice on her 19" rims. The dealer dropped it off last night and said they started getting an error warning on the way to our house.

I checked the selections on the control and it only shows 18" tires in the winter tire category which is what the dealer had selected. The 19" tires are only shown in the summer tire category.

We have the TPMS turned off because of the error.

Can the control have a 19" winter tire added to the list or do we select the 19" summer or 18" winter? We've had previous problems with the TPMS receiver (replaced twice so far) so the error code may not be a result of the tire selection.

-Ken

Zin

Ken,
I'll be interested to hear the answer, as I am planning on doing the same thing you did with the 19" tires.
Hmmmm.....

johnsamonas

Just select summer 19".

I have the TPMS with my 22"s, and as there is no setting for 22"s,I have selected summer 20" and it works fine.

pdxjim

So, I ask the question, what difference does it make to the car when selecting the different sizes? Anyone know??

skl

So they make 19 winter tires now eh? Oh well, I"m sure TireRAck enjoys my business and my 18 winters work fine and unfortunately will need to go on here soon...

johnsamonas

I think it is because there are different pressures recommended for winter use,the computer may allow different parameters for pressure loss before sounding the alarm.

It sometimes happens in my car with the 22's on,the low tyre pressure warning has come on but the tyre is just 0.1 bar less than what it should be.But I think this is a fault because there is no setting for 22's.

I can still see my tyre pressures though.

kc.beach

Zin,
My wife says you're going to love the 19" Ice & Snow Scorpions. The ride is much smoother and it "finally feels right". I noticed the same difference on my 18s between the stock and winter tires (I've switched back and forth twice now). Her's now feels the same as mine with the winters (most comfortable). Up until now I thought it was due to the 1" less sidewall but I now see the tire type makes a big difference.

But the question remains:

Can the TPMS selections be upgraded to reflect the 19" winter tire that is now recommended by Porsche?

-Ken

ML

I ran the 19" Ice & Snow Scorpions last winter. Same issue with the TPMS. I set it using the winter 18" setting. If I recall correctly, the system first reported an error but after a reset, was fine. I would just double check the pressure with an external gage to make sure that the reading is accurate (not sure if the TPMS is a real "internal gage" or if it uses some form of algorithm that would factor in the internal volume of the tire) and use the TPMS just to monitor any variations.

Love the tires by the way.

kc.beach

ML,
Your advice worked. I'm using the 18" winter setting and everything has been fine the last 3 days after performing a system reset. The tire pressures are correct.

I'll try and find out more on this from our dealer and will post if anything new is learned.
-Ken