Pirtelli PZeros tread pattern

[alan718]

Hi
New member here. Purchased a Used Approved 2020 base Cayman 6 weeks ago and just joined the PCGB..

This is my first Porsche and we did not get off to a very happy start because I had to make a warranty claim almost immediately. However that was dealt with efficiently by my local OPC and has now been fixed (I hope!).

I now have a query about tyres. I’m more curious than anything else.

The car has 20 inch wheels fitted with Pirelli PZero’s all round.

The offside rear tyre is less worn than the nearside. I understand that this due to the tyre being replaced due to suffering a non-repairable puncture. (See image).

The offside rear tyre has a very thin grooved tread on the outside shoulder of the tyre. There do not appear to be any wear bars in this groove. This groove is entirely absent from the outside shoulder of the nearside tyre. Possibly worn away?

Now comes the numpty question. Is the nearside tyre legal?

The reason I ask is that the legal requirement is the tread has to have a minimum of 1.6 mm depth across the central 75% part of the tyre. If my calculations are correct the central 75% starts and ends 33 mm from the sides of the tyre.

If that is indeed the case, it suggests that the tyre is illegal as the thin grooved tread on the outside shoulder of the tyre is entirely absent.

BTW. Before I purchased the car I asked the OPC for the tread data used as part of the 111 point check and they only provided it for the 4 other grooves for all the tyres.

 

[AngieS]

Hi Alan
The OPC would have red flagged if concerned as obviously they may get opportunity to change. My experience is even though tyres may be considered legal, things like age can play a huge part. My set of PZeros are in garage with 14k on them but I just think they’re a bit ’crispy’ now, showing crazing etc. Obviously when you consider spirited driving options, these are what keep you on the ground so if in doubt I’d change them.


pic shows my stack with front on top of rear. Tread pattern may well have been superseded by P.

 

[GordonT]

Hi Alan,

Welcome to the club. Let me say straight away that I am not a tyre expert so this is a layman’s response, however I would certainly say that your tyres are legal. I remember how shocked I was the first time I took the (Pirelli) rears off my car. The absence of "tread” on the outer made me wonder what was going on.

Remember that there are different rubbers in different parts of the tyre. The outer area is like a slick to give maximum lateral grip on a road going tyre. I’m going to stop now and hope some knowledgeable person will give you a more technical response! (How much do you know about tyres, Jeff?).

Gordon.

 

[Motorhead]

Ha,ha! Not a lot more than you Gordon … other than that they’re black and round and - along with the brakes - are the most important component on car!??

My own experience is also similar to yours, and would agree that Alan’s tyres are legal since tread depth generally is measured on grooves where the tread bars are located.

Addressing your original post Alan, I’d recommend that you get a full geometry check to ensure that the suspension is within Porsche's specified tolerances.

Jeff

 

[Greenman986S]

If you bought from OPC, legal requirement is irrelevant as Porsche mandate N rated tyres less than 5 years old with 3mm of tread.

 

[AngieS]

Would be good to see a copy of mandate as certainly both our cars went through OPC checks with tyres older than 5 years. I even pointed out the crazing and was advised not an issue.
Side issue, the cold weather certainly has an impact on tyres. Moved ours for first time in a couple of weeks and the scrubbing from slow steering was noticeably more harsh than back in the warmer stuff.

 

[alan718]

Hi

Thanks for the feedback guys.

I've now invested in a digital tread depth indicator. The old mechanocal one I have is fairly accurate but the digital one is easier to use/read.

Next up - I'm now considering grillles for the front radiators. I see that there is a Zunsport thread on here which I will now study!

Thanks again.

 

[Greenman986S]

Would be good to see a copy of mandate as certainly both our cars went through OPC checks with tyres older than 5 years. I even pointed out the crazing and was advised not an issue.
Side issue, the cold weather certainly has an impact on tyres. Moved ours for first time in a couple of weeks and the scrubbing from slow steering was noticeably more harsh than back in the warmer stuff.

try getting / renewing an OPC warranty without meeting those criteria.

see also any OPC used car section under "why buy from us"

 

[AndrewCS]

Not come across the 5 year limit - standard in any Porsche documentation ?

Porsche 111-point check - Porsche Great Britain

Wheels and tyres: tyres are safety-critical and transmit the high power of Porsche vehicles to the road or other surfaces. Checking whether the correct, Porsche ‘N’ rated tyres are fitted is exceptionally important. All tyres are checked to ensure they are free from damage and that they have a minimum tread depth of 3mm, as the Porsche Approved standards dictate.

 

[BrianJ]

Not come across the 5 year limit - standard in any Porsche documentation ?

I found this somewhere once but can’t find it now. Wasn’t where I expected it to be. OPC from whom I bought my car in 2022 told me Porsche won’t let them sell Approved Used cars with tyres older than 5 years.

 

[AndrewCS]

... but they will let them sell the cars with `cracked` PZero N0`s []

 

[AngieS]

Would be good to have an area in club forum where input on product range is useful to establish our feedback. From my own experienc, most of the main tyre manufacturers have great and poor performance tyres. I prefer Michelin but hear nothing but agro about Cup2’s in wet conditions. My crispy 20” P’0’s are very legal and Porsche OK’d but just don’t like them. I obtained some 19" Good Years on S alloys and found them a great all rounder on Euro Tour. Some tyre manufacturers aren’t what they used to be. IN MY experience, Avons are nothing like they used to be. So many ‘best tyre’ websites opinions but real life views and experience is far better. A rating out of 10? We‘d soon get an average. To sum it up, ours are currently at OPC for non related issues! Loan car is a NEW Cayenne. it has Hankooks and it’s like a sailing ship….i think it’s the tyres.

 

[AngieS]

This post is about tyres…..but re age/replacement dates, what About Airbags? They have expiry dates but again not bemoaned by OpC’s.

 

[AndrewCS]

Cup 2`s are fine in the wet (but not the cold) except a monsoon // PZero N0`s are also OK, even when `cracked`

So many variables with regard to preference - expectation - knowledge - ability etc .... []

 

[Mcmikey62]

Hi

Thanks for the feedback guys.

I've now invested in a digital tread depth indicator. The old mechanocal one I have is fairly accurate but the digital one is easier to use/read.

Next up - I'm now considering grillles for the front radiators. I see that there is a Zunsport thread on here which I will now study!

Thanks again.

Just fitted the Zunsports to my 718 GTS, look fine and an easy fit for an amateur. There is a thread on here that has updatedd from people helping me with the fitting. Look good on the car and happy with them.