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Tyre wear how low would you go

markiii

Imola
Joined
7 Mar 2011
Messages
757
so chaps collective wisdom appreciated

I have a suspension issues which I won't go into at the moment which Chris at COG is going to be sorting for me, but rather than assume its mechanical aznd dive straight in he suggested I pop into an OPC and have them check that the PASM controller is working correctly before hand.

I've been into Hatfield this morning who I suppose positively, whilst not having a view on the cause of the issue have confirmed the PASM controller as working and that they also feel the same issue when driving it that both Chris and myself do

however they also were concerned about my Non N rated Pilot SuperSports (no surprise there)

currently these tyres have around 20K on them over circa 2 years and despite having a hard life are still pretty good in tread levels as below

OSF and NSF 5mm/5mm/4mm across the tyre outside to inside
OSR and NSR 4mm/4mm/3mm across the tyre outside to inside

to me this still seems pretty good and on any other car/tyres I've owned I wouldn't dream of changing them yet.

However I'm told by Hatfield that Porsche recommend changing at the point any part of the tyre reaches 3mm. Whilst I'm not too concerned if I have to change them as 20K is more than I was expecting from a set anyway. I don't really want to burn a grand if its not needed.

So thought on 4wd 997s and or PSS, would this be worth doing or is it just OPC trying to convince me to to go N rated in the process
 
Stopping distances rapidly increase with tyre wear and I would assume the risk of aquaplaning would do to. Porsche is a performance car so they will err on the side of caution

The legal limit for minimum depth of the tread on your tyres is 1.6 millimetres, across the central ¾ of the tread around the complete circumference of the tyre.

For safety reasons it is recommended that you replace your tyres before the legal limit is reached. Many vehicle manufacturers recommend replacing at 3 millimetres. To see the impact on braking distance of different tyre tread depths. At 1.6 millimetres in wet weather it takes an extra car length (8 metres) to stop at 50 mph than if your tread was 3 millimetres.

http://www.kwik-fit.com/uk-tyre-law.asp

PS Sure they want your money but they also want to keep you alive so they can sell you more tyres
 

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all good stuff

so would you change the rears at those levels?
 
Personally it would depend upon the time of year - if we were approaching summer I would leave them on until now / winter, however as we are approaching bad weather time I'd either pull on a set of Winter boots and keep these for next summer or replace them and sell the old ones on ebay. (assuming you use your car as a daily drive)
 
Mark, that is my understanding also. I'm not advocating waiting til 1.6mm which is the legal limit in this country in case some master vulcaniser tells me this is fool hardy and they should be changed earlier.

The non-N rated is probably more worrying than this gentleman's tread depths - I've never driven on such tyres, but given the high performance, then that N-rating must be there for a reason.
 
N rating means nowt, I'd take a set of MPSS over a set of MPS2 N-rated any day of the week, they're a much superior tyre in every aspect. Have you really never driven a performance car other than a Porsche? Genuine question, not meaning to sound arsey.

I'd consider changing at 3mm, but it would have to be a uniform 3mm across the tread i.e. 3-3-3, not 4-4-3. That is of course, unless you have any other concerns about the tyres...
 
The Porsche Turbo is the first supercar I've owned and driven. So I have no experience of driving one without N rated tyres. I was told that N rating is important and a load of reasons given - most of which I can't remember. But then I've a full set of Conti's N2 all-round so I'm not in a decision about this.

Re: even wear across the tread. I was not aware that Porsche's wear ecvenly due to the inherent negative camber (on the rears at any rate) which would always mean the car has more wear on the inside edge than the outside. I did hear a guy in the US talking about setting camber to Zero and getting 20k miles out of a set of rears - no idea what happened whne he tried to turn a corner though with Zero Camber (and NO I'm not a geo specialist - just someone who undersatnds these cars are meant to be set up in a certain way for a certain reason).
 
mark pearce said:
I thought the limit in Germany was 3mm hence where Porsche get their recommendation from?
#

Believe you are correct but 'think' it only applies to winter tyres and the summer tyres are the same min tread depth as for UK cars (1.6mm). I do seem to recall that the AA recommend a minimum of 3mm if driving in the wet which makes sense to me considering how quickly the stopping distance seems to drop off on the graph.

Seems the OP is doing approx 800 miles pm so come the end of November I suspect he might want to get those rears changed.
 
cheshire911 said:
The Porsche Turbo is the first supercar I've owned and driven. So I have no experience of driving one without N rated tyres. I was told that N rating is important and a load of reasons given - most of which I can't remember. But then I've a full set of Conti's N2 all-round so I'm not in a decision about this.
No other performance cars though? I'm thinking anything with 300bhp+ really, so Imprezas or Astons or AMGs etc. None of those have a requirement for ratings, and they're just as likely to be driven hard as a Porker is.

I'm on N-rated 050As, but only for warranty reasons. I see it as more of a way to screw money out of people than any genuine performance/safety reason. Whilst I can believe that an N-rated tyre will perform better than the non N-rated equivalent, I also don't think that anyone outside of professional race drivers would ever tell the difference on road or track.


Anyhoo, rant over, as you were! :oops:
 
I am mature enough to realise that there may be many marketing dimensions on these things. It may well be true that for normal road use there isn't a jot of difference between n and Non-N rated tyres. But soem insurers require it, some warranties require it, and there is a herd of lemmings all brain-washed that non-N-rated = non-standard = bad news.

A good Company can create wonders through good marketeers.

The only caar I am close to on your list of supercars is in badge only - a daily driver Merc E-Class from new. Not AMG or anyhting but a diesel that averages over 45mpg on long runs and can easily hit 52mpg on 70mph cruise control on a motorway run from Knutsford M6 to Hendon at the foot of the M1. No supercar but just glides along and whisper quiet.
 
Ekona said:
cheshire911 said:
The Porsche Turbo is the first supercar I've owned and driven. So I have no experience of driving one without N rated tyres. I was told that N rating is important and a load of reasons given - most of which I can't remember. But then I've a full set of Conti's N2 all-round so I'm not in a decision about this.
No other performance cars though? I'm thinking anything with 300bhp+ really, so Imprezas or Astons or AMGs etc. None of those have a requirement for ratings, and they're just as likely to be driven hard as a Porker is.

I'm on N-rated 050As, but only for warranty reasons. I see it as more of a way to screw money out of people than any genuine performance/safety reason. Whilst I can believe that an N-rated tyre will perform better than the non N-rated equivalent, I also don't think that anyone outside of professional race drivers would ever tell the difference on road or track.


Anyhow, rant over, as you were! :oops:

I suspect the N rating is not relevant in UK were the speed limit is 70mph. But don't forget it's a German car being sold to Germans who can head off to the Autobahn and hit silly speeds (everyday if they want) - the stress on the tyre must be quite considerable at 200mph.

Seem to recall you need to replace the tyres on a Bugatti Veyron every 3,000 miles for the same reason
 
thanks guys tbh its not a daily, barely comes out in the bad weather and tends to get most of its miles in big chunks with roadtrips such as this years 3000km in 10 days tour of france and Monaco

the whole suspension discussion were initiated as a result of the last big roadtrip when I scared the ***** out of myself trying to come down the col turini at very pedestrian speeds in the cold and wet on a concrete surface

a full on 4 wheel drift was not what I had in mind in those conditions
 
apw2007 said:
Ekona said:
cheshire911 said:
The Porsche Turbo is the first supercar I've owned and driven. So I have no experience of driving one without N rated tyres. I was told that N rating is important and a load of reasons given - most of which I can't remember. But then I've a full set of Conti's N2 all-round so I'm not in a decision about this.
No other performance cars though? I'm thinking anything with 300bhp+ really, so Imprezas or Astons or AMGs etc. None of those have a requirement for ratings, and they're just as likely to be driven hard as a Porker is.

I'm on N-rated 050As, but only for warranty reasons. I see it as more of a way to screw money out of people than any genuine performance/safety reason. Whilst I can believe that an N-rated tyre will perform better than the non N-rated equivalent, I also don't think that anyone outside of professional race drivers would ever tell the difference on road or track.


Anyhow, rant over, as you were! :oops:

I suspect the N rating is not relevant in UK were the speed limit is 70mph. But don't forget it's a German car being sold to Germans who can head off to the Autobahn and hit silly speeds (everyday if they want) - the stress on the tyre must be quite considerable at 200mph.

Seem to recall you need to replace the tyres on a Bugatti Veyron every 3,000 miles for the same reason

surely suitability for such is determined by speed and load ratings, not an N?
 
I thought the N rated tyres are those developed by Porsche in conjunction with the tyre manufacturer. They selling high performance cars so assume they only protecting themselves (from being sued) and their customers (from killing themselves) :dont know:
 

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