996 TT.... time for new tyres

[jules c]

My Pirelli P-zero Asimmetrico (295/30 zr18 n3 rear, 225/40 zr18 n3 front) are due for change pretty soon.

I have heard that the Pirelli's are pretty soft compound and therefore wear pretty quick. I don't track the car so ultimate grip is not an issue. Does anyone have any experiences of the following tyres?

Michelin Pilot Sport 2 N2
Michelin Pilot Sport N1
Bridgestone s02 N3
Pirelli Pzero Corsa N6
Pirelli Pzero Rosso N5
Continental Conti-Sport Contact 2 N2

What does the N1-N6 rating refer to..?

Cheers......

[pat cash]

The N rating is Porsche specific - it means that the particular tyre with that N rating has been designed/constructed to meet specific tolerances tested within Porsches specification, therefore demonstrates the characteristics required for the vehicle. The first time a new tyre type is tested it is given the rating N0. Every time the design changes (- this could be anything from the compound changing to the lettering on the side wall!) The tyre is retested then becoming N1 etc etc etc.

Its amazing how critical this can be - you can take tyres that look, smell even taste the same, one being N rated and the other not and end up with all sorts of strange effects. I saw a car once where the PSM physically bought the car to a complete standstill everytime it went around a corner even at low speed - turned out to be non N rated tyres....

Edited by pat cash on Thursday 12th October 14:04

[GreigM]

pat cash said:

I saw a car once where the PSM physically bought the car to a complete standstill everytime it went around a corner even at low speed - turned out to be non N rated tyres....

It may have been that set of non n-rated tyres, but its more likely that the tyres were defective in some manner which was giving a misleading sensor reading to the PSM. In my previous boxster I used a mix of N and non-N rated tyres for track use and the PSM never complained so long as the pressures were set correctly and the size ratios between front/rear was consistent - there's no way PSM could detect you have non n-rated tyres.

[jules c]

I would imagine if Porsche specify "N" rated tyres for car, then insurance companies will need to see the same... you know how picky they can be should a claim arise!

Any feed back on the other tyre brands or different Pirelli options?

Cheers
J

[GreigM]

jules c said:

I would imagine if Porsche specify "N" rated tyres for car, then insurance companies will need to see the same... you know how picky they can be should a claim arise!

no, as long as the tyre is street legal and speed rated sufficiently then you can put whatever rubber you like on the wheels so long as it would pass an MoT. There's barely a GT3 on the road which uses N-rated tyres as most use super-sticky semi-slicks.

N-rated tyres are usually a slightly different pattern which benefits the dynamics of the car, and/or a softer stickier compound. This is usually at the expense of longevity, but porsche reckon the owners of its car can afford the increased wear rates.

[jonny996]

kwick fit have a deal on this week WEB only 25% off perrillis

[pat cash]

GreigM said:

pat cash said:

I saw a car once where the PSM physically bought the car to a complete standstill everytime it went around a corner even at low speed - turned out to be non N rated tyres....

It may have been that set of non n-rated tyres, but its more likely that the tyres were defective in some manner which was giving a misleading sensor reading to the PSM. In my previous boxster I used a mix of N and non-N rated tyres for track use and the PSM never complained so long as the pressures were set correctly and the size ratios between front/rear was consistent - there's no way PSM could detect you have non n-rated tyres.

In this case it was N rated on one wheel on one axle and non n rated on the other. It came down to a difference in expansion rates at certain temperatures leading to a perceived wheel speed difference on the same axle. At this point PSM first uses its ABD function to brake the wheel that has 'lost traction'. As it actually hadn't and the wheel speeds couldn't be balanced the ASR function then shut the throttle - eventually bringing the car to a standstill.

You're correct - PSM can't detect whether you have N rated tyres on or not, but it can detect the consequences....

[pat cash]

jules c said:

I would imagine if Porsche specify "N" rated tyres for car, then insurance companies will need to see the same... you know how picky they can be should a claim arise!

Any feed back on the other tyre brands or different Pirelli options?

Cheers
J

Many insurers are now aware that Porsche N rate their tyres - They also know that in your owners hand book it states
'Sizes of tyres and wheels are only approved for use following extensive tests.
Your Porsche partner will be pleased to advise you about the current approval status.
If you refit your vehicle with tyres or wheels not authorised by Porsche, this may have a
dangerous effect on driving stability.' And 'Use only tyre makes tested and approved by
Porsche.'

I'm led to believe that these factors are now being considered in claims....

[jules c]

John,

My concerns exactly.

Still no word from anyone on experience with other tyre brands but I guess if I stick with N rated (ie Porsche approved) I shouldn't go far wrong?

I see most tyre suppliers state "Porsche" after the tyre details also.

Thanks for the help