Porsche Cayman tyre information
Porsche Cayman tyre information
Author
Discussion

smmjh11

Original Poster:

21 posts

175 months

Sunday 17th March 2013
quotequote all
Hi

Is there an updated list online that shows the tyres that Porsche approve. I have a Cayman that will need a new set of rear tyres as when I went to check the tyre pressure today I noticed that the middle of the rear tyres seems to be well worn bordering on illegal by the looks of them.The car is not driven that much in the winter and I cannot believe that the wear has happenedso quickly as they looked pretty even the last time I checked. I am led to believe through searching the internet that this could be due to over inflating. I have 235/35 ZR19 (87Y) Pirelli P zero on the front which I set the pressure at 32psi, and the rear tyres are 265/35 ZR19 (94Y) also Pirelli P zero which I set the pressure to 37psi. The tyre settings I use are from the data badge on the drivers side are these correct or is the cause due to me over inflating the rear tyres as I have had the car for about 20 months now and not done anything different so cannot understand the sudden wear on the tyres.

From the servicing information I have from the previous owner the rear tyres seem to have done around 12000 miles so is this about right for a set of rears as the outside and the inside of the rear tyres seem to have plenty of tread left on them. When it was serviced last May the tyre readings were 3.3 3.7 5.8 (NSR) and 3.7 4.3 6.0 (OSR) and I have only done about 2000 miles since.

From what I have read on the forum a lot of people recommend the Michelin PS2 tyres can I fit these with the Pirelli's I have at the front or do I need to stick with getting a couple of new Pirelli's.

Regards

Mark


Martian O

2,734 posts

192 months

Sunday 17th March 2013
quotequote all
Sounds like the tyres are over-inflated to cause this wear pattern.

I think the general consensus is, with extended warranty - Michelin Pilot Sport 2s, without warranty - Michelin Pilot Super Sports.

SeaBox

89 posts

222 months

Sunday 17th March 2013
quotequote all
I have the same size tyres on my Cayman 2.9 and according to my door sticker the rears should be 34psi. I have Michelin PS2s and they are wearing very evenly on those pressures.

smmjh11 said:
Hi

Is there an updated list online that shows the tyres that Porsche approve. I have a Cayman that will need a new set of rear tyres as when I went to check the tyre pressure today I noticed that the middle of the rear tyres seems to be well worn bordering on illegal by the looks of them.The car is not driven that much in the winter and I cannot believe that the wear has happenedso quickly as they looked pretty even the last time I checked. I am led to believe through searching the internet that this could be due to over inflating. I have 235/35 ZR19 (87Y) Pirelli P zero on the front which I set the pressure at 32psi, and the rear tyres are 265/35 ZR19 (94Y) also Pirelli P zero which I set the pressure to 37psi. The tyre settings I use are from the data badge on the drivers side are these correct or is the cause due to me over inflating the rear tyres as I have had the car for about 20 months now and not done anything different so cannot understand the sudden wear on the tyres.

From the servicing information I have from the previous owner the rear tyres seem to have done around 12000 miles so is this about right for a set of rears as the outside and the inside of the rear tyres seem to have plenty of tread left on them. When it was serviced last May the tyre readings were 3.3 3.7 5.8 (NSR) and 3.7 4.3 6.0 (OSR) and I have only done about 2000 miles since.

From what I have read on the forum a lot of people recommend the Michelin PS2 tyres can I fit these with the Pirelli's I have at the front or do I need to stick with getting a couple of new Pirelli's.

Regards

Mark

SeaBox

89 posts

222 months

Sunday 17th March 2013
quotequote all
I have the same size tyres on my Cayman 2.9 and according to my door sticker the rears should be 34psi. I have Michelin PS2s and they are wearing very evenly on those pressures.

smmjh11 said:
Hi

Is there an updated list online that shows the tyres that Porsche approve. I have a Cayman that will need a new set of rear tyres as when I went to check the tyre pressure today I noticed that the middle of the rear tyres seems to be well worn bordering on illegal by the looks of them.The car is not driven that much in the winter and I cannot believe that the wear has happenedso quickly as they looked pretty even the last time I checked. I am led to believe through searching the internet that this could be due to over inflating. I have 235/35 ZR19 (87Y) Pirelli P zero on the front which I set the pressure at 32psi, and the rear tyres are 265/35 ZR19 (94Y) also Pirelli P zero which I set the pressure to 37psi. The tyre settings I use are from the data badge on the drivers side are these correct or is the cause due to me over inflating the rear tyres as I have had the car for about 20 months now and not done anything different so cannot understand the sudden wear on the tyres.

From the servicing information I have from the previous owner the rear tyres seem to have done around 12000 miles so is this about right for a set of rears as the outside and the inside of the rear tyres seem to have plenty of tread left on them. When it was serviced last May the tyre readings were 3.3 3.7 5.8 (NSR) and 3.7 4.3 6.0 (OSR) and I have only done about 2000 miles since.

From what I have read on the forum a lot of people recommend the Michelin PS2 tyres can I fit these with the Pirelli's I have at the front or do I need to stick with getting a couple of new Pirelli's.

Regards

Mark

SeaBox

89 posts

222 months

Sunday 17th March 2013
quotequote all
I have the same size tyres on my Cayman 2.9 and according to my door sticker the rears should be 34psi. I have Michelin PS2s and they are wearing very evenly on those pressures.

smmjh11 said:
Hi

Is there an updated list online that shows the tyres that Porsche approve. I have a Cayman that will need a new set of rear tyres as when I went to check the tyre pressure today I noticed that the middle of the rear tyres seems to be well worn bordering on illegal by the looks of them.The car is not driven that much in the winter and I cannot believe that the wear has happenedso quickly as they looked pretty even the last time I checked. I am led to believe through searching the internet that this could be due to over inflating. I have 235/35 ZR19 (87Y) Pirelli P zero on the front which I set the pressure at 32psi, and the rear tyres are 265/35 ZR19 (94Y) also Pirelli P zero which I set the pressure to 37psi. The tyre settings I use are from the data badge on the drivers side are these correct or is the cause due to me over inflating the rear tyres as I have had the car for about 20 months now and not done anything different so cannot understand the sudden wear on the tyres.

From the servicing information I have from the previous owner the rear tyres seem to have done around 12000 miles so is this about right for a set of rears as the outside and the inside of the rear tyres seem to have plenty of tread left on them. When it was serviced last May the tyre readings were 3.3 3.7 5.8 (NSR) and 3.7 4.3 6.0 (OSR) and I have only done about 2000 miles since.

From what I have read on the forum a lot of people recommend the Michelin PS2 tyres can I fit these with the Pirelli's I have at the front or do I need to stick with getting a couple of new Pirelli's.

Regards

Mark

Matt Seabrook

563 posts

281 months

Sunday 17th March 2013
quotequote all
Do you use the car for lots of motorway or higher speed driving?

mrdemon

21,146 posts

295 months

Sunday 17th March 2013
quotequote all
I run 31 rear :-) so 37 sounds very high.


Pss are best

Zyp

16,102 posts

219 months

Sunday 17th March 2013
quotequote all
Look a bit like this?



My rear Pirellis, 7500 miles, Boxster Spyder.
According to Pirelli that's how they are supposed to wear!

Never over inflated, but I've since learned that you should drop the stated pressures by a few psi.

smmjh11

Original Poster:

21 posts

175 months

Sunday 17th March 2013
quotequote all
Matt - General use really not much motorway or high speed driving.

Mr Demon - Consensus seems to drop by a few psi but I suppose the damage is done on my tyres for now.

Zyp - spot on that is exactly what my rear tyres look like.

Thank you all for taking the time to respond

Trev450

6,757 posts

202 months

Monday 18th March 2013
quotequote all
I have a Cayman S with the exact same size tyres and run my rears at 35psi and find they wear quite evenly.

The general advice is not to mix brands of tyres so either replace the rears with Pirelli, or better still sell the fronts on ebay and get yourself some Michelins all round.


HokumPokum

2,089 posts

235 months

Monday 18th March 2013
quotequote all
manufacturer tire pressure is for ambient of 20 degrees C. Please compensate for drop in temps by checking your manual.

otherwise, use the ideal gas law equation............

jadatis

36 posts

219 months

Monday 18th March 2013
quotequote all
You can lower the pressure , and even get more gripp and comfort, and a more even wear.
But the sidewalls cant stand the deflection then and get damaged.

Tyre pressure is all about load on the tire and a bit about speed , even less about camber angle ( alignment).

I kept myself busy with tyre-pressure calculation with the formula and system the European tyre-makers used for decades.
Found out much about tyres, and one thing I lately discovered, is, that low aspect ratio tyres ( the 40 in your tyres) are calculated to high in their maximum load.
This means that you have to use high pressures to compensate that . All is to prefent the sidewalls from damaging.

To calculate a save pressure , I need the Gross axle weights , and maximum used speed . From the tyres I can read it from your information given, but need to know if they are reinforced/Extraload/XL or not.
Then I can calculate a save pressure for if you are fully loaded and ride maximum speed.
If you can produce the real weights on the front and back-axle in normal use, I can calculate a save pressure for that.
then I will use the reduced maximum load for save deflection, and use my own formula wich is a combination of the old , and a new one I found, and to my opinion, comes the closest to the ever to be constructed ideal formula

Greatings from Holland
Peter

gsewell

721 posts

313 months

Tuesday 19th March 2013
quotequote all
I cannot see whether your car is gen1 or gen2 - however for the gen2 from the owners manual (page 196) it says 19" wheels front 2.2bar (32psi) rear 2.3bar (34psi).

Richard Hamilton

525 posts

291 months

Tuesday 19th March 2013
quotequote all
OP - drop me a PM and I'll email you the latest Approved Tyres list. Let me know if it is Gen1 or Gen2, as they are different lists.

smmjh11

Original Poster:

21 posts

175 months

Tuesday 19th March 2013
quotequote all
My car is a Gen 1 and the book I had was a cayman S which stated 32 for the front and 36 for the rear. But the label on the drivers side states 32 & 37 respectively.

Mark

gsewell

721 posts

313 months

Wednesday 20th March 2013
quotequote all
I doubt that 1 psi over inflation will make much difference unless your gauge is under-reading.