Is this statement true about N rated tyres?

I found this on an American Site.... N rating .... I don't consider to be a factor. By sheer chance, I was in Zuffenhausen and visited the big Porsche Zentrum dealer adjacent to the factory just prior to making my decision. A lengthy discussion with the staff there led me to understand that N-rating is an "after the fact blessing" of a tire, as opposed to the oft assumed sign of "made to order for Porsche". A salesman went to a new car and pulled out the owner's manual. He pointed out that: (1) it only mentions N rating in the context of matching mounted sets of the same N-rating. (2) it specifically mentions buying non-Porsche recommended tires and simply reminds one to buy from a reputable dealer and adhere to the specified quality (speed, traction, wear, etc) ratings. Bottom line of the discussion, the use of N-rated tires is not seen by Porsche as a requirement in any way. This has been skewed somewhat by a deal between Michelin and US Porsche dealers to have the dealers as exclusive outlets for some Michelin N-rated tires .... thus assuring a recommendation from the dealer that "you must use N-rated tire". I'm still tempted with the Yoko's T1R's which are not N rated! Cheers

I understand that N rating is for tyres that have been tested and approved by Porsche for use on it's cars. This does not constitute a legal or compulsory requirement. Although I assume some insurance companies might beg to differ.

996dom I agree with Geoff - The tyres that are on the approved list are the ones that your insurance company cannot quibble about in the event of the unthinkable. If you want to use something else, then the best advice would be to get written agreement with your insurance company before you fit them. I have experience of an insurance assessor questioning the aftermarket alloys on my daughters car and was about to reject the claim. Fortunately we let them know when they were fitted, so he didn't have a leg to stand on. If you want a copy of the Porsche TSB on approved tyres, email me.

Thanks for the replies! I cannot believe that an Insurance company can refuse to settle a claim because the car did not have Porsche 'recommended' tyres fitted. As long as the tyre fitted is the correct size and the correct speed rating then surely there can be no arguement! I'll understand if I had shoehorned some 22" bling spinners on shod with 445/10 - 22 tyres and not informed the insurance company of my upgrade, but all I want is to fit standard size tyres on the standard 18" rims. Has anyone had a claim refused on the basis that they didn't have N rated tyres fitted? Has anyone got any proof that the N rated tyres are not 'an after the fact blessing' as claimed in the quote on my first post? I've got my transport manager to speak to my insurance company to see what they say, just to be 100% certain. Cheers

Getting tyres rated is quite an expensive business for both Porsche and the tyre manufacturers and the fact that they do not charge you more for N-rated tyres shows that there is no hidden agenda to lock you in with the few manufacturers who have had their tyres N-rated. In fact at Costco, where I get my Michelins, the N-rated are a couple of quid cheaper than the same equivalent non-N rated tyres. On top of insurance and warranty claim issues which have been stated above, you will have money deduced for the wheels when you come to sell your car (unless you sell it privately and the buyers doesn't know about the Porsche N-rating)

N-Rated tyres are tested by Porsche to give the best possible characteristics to whichever model they are destined to be fitted to. I believe Porsche have been known to refuse N-ratings to tyres in the past. Whether tyre manufacturers actually design compounds for use in N-rated tyres I dont know. However, a LHD 993 that I owned was imported from Germany, and the equivalent to the MOT certificate actually specified which tyres had to be fitted to the car for the certificate to be valid - obviously only applied to the German regulations - particularly as the dealer I bought the car from had fitted Hankook tyres to the car. which handled like a complete dog with them. It wasn't until I fitted Bridgestones to it that I realised that you could accelerate around gentle curves!!!

Try driving a 996 with non N-rated Bridgestone SO2s and you'll see why it's best to stick to N rated tyres. (There are two types of SO2 and a lot of tyre fitters won't know or care).

Have you driven a 996 with normal SO2's and N rated SO2's? If so what was the difference between them! Cheers

Whatever you think about N rated tyres it's wrong to think that the N rating is an after-the-fact rubber stamping exercise that Porsche performs. The fact is that Porsche work with the tyre manufacturers over an extended period of time during the design and development of a tyre and complete a comprehensive testing process to end up with a tyre that is specifically designed to get the best out of the car given the suspension set up and geometry. The construction of N rated tyres are different to their non-N rated equivalent. It is not a case of the manufacturer tossing a set or two of tyres over to Porsche saying "try those on for size Jimmy" before getting approval. I'm sure that the vast majority of us would not be able to detect any difference in normal road driving unless you do alot of track work and are used to driving the car close to, or on the limit regularly to appreciate it. At the end of the day the price difference between N rated tyres and the non-N rated equivalent is negligible - less than a tenner if you shop around so in my view you may as well fit them than not. We all make sure we spend top dollar on top quality oil on Porsche's recommendation so why question their recommendation for tyres when ultimately if there is any single component on the car you don't want to be scrimping on its the tyres.

Thanks for the replies. It seems that most people are confident that the N rated is not an after the fact blessing and that Porsche have the tyre companies manufacture various bespoke tyres which are vigourously tested by Porsche and only given a N rating when they suit the individual characteristic's on each model. If this is the case I understand that it will be foolish to ignore the N rating and to choose one of the 3 options that have the N rating. Just out of interest, does any other Marque have a similar rating system as Porsches? Anyone tell the best place to source a set of P Zero's[ ] Cheers

Here is a tech article about N-Spec tyres: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=26 I know Jaguar have a similar system to Porsche, and if I recall, so do Ferrari For a good deal on tyres try Elite Garages - details in Porsche Post - a great deal for members.

These are choice of manufacturers you have for Porsche, could be more by now as this is from one of the 2003 Christophorus: Bridgestone Continental Dunlop Michelin Pirelli Yokohama

Here is an extract from the Porsche TSB: 205/50 ZR 17 and 255/40 ZR 17 Bridgestone Potenza S-02A N4 Directional Continental SportContact 2 N2 Specific side only Michelin Pilot Sport N2 Directional Pirelli PZero Rosso N3 Specific side only 225/40 ZR 18 (1) and 265/35 ZR 18 (1) Continental SportContact 2 N2 Specific side only Dunlop SP Sport 9090 NO Directional Michelin Pilot Sport TL Nl Directional Pirelli PZero Rosso N4 Specific side only 225/40 ZR 18 and 285/30 ZR 18 Bridgestone Potenza S-02A N3 Directional Continental SportContact 2 N2 Specific side only Michelin Pilot Sport Nl Directional Pirelli PZero Rosso N4 Specific side only 225/40 ZR 18 and 295/30 ZR 18 Continental SportContact 2 N2 Specific side only Pirelli PZero Asimmetrico N3 Specific side only 225/40 ZR 18 and 295/30 ZR 18 XL Bridgestone Potenza S-02A N3 Directional Michelin Pilot Sport Nl Directional Footnote: (1) = Only for vehicles up to and including Model Year 2001 (1).

Richard, or anyone else.. Any idea what the 'XL' means after the sizes for the last pair?

I hadn't given it a thought until you noticed it. The Continental Web site says "XL - Extra Load (designates specially reinforced tyres)".

That makes sense...cheers.

My understanding is that theoretically you should not mix tyres of different N ratings, any more than you should mix different patterns from the same manufacturer. Imagine my surprise when I found that my rear tyres 295/30/18 are available as Rosso's rated N5, but Pirelli have no N5 rated Rosso's for the fronts (225/40/18). It would seem that the only way I could achieve a full set of Pirellis with matching N ratings was to go for PZero System Assimetrico rather than Rosso. I have ended up going for the Bridgestone SO2 N3's all round

You certainly shouldn't mix different N ratings or N-rated and non-N-rated tyres on the same axel but I think it's good and safe practice to have a matched axel-set of tyres anyway. I'm not 100% sure on mixing different N rating between the front and rear axels though, i've read mixed reviews on this.

David, How are you finding the SO2's? Dom

Not being fitted until next Tuesday. Will report back. It will be interesting because I am big fan of my existing Yokohama AVS Sports, which I have used on previous cars as well.

Yes, hence my comment. I ordered a pair of new SO2s a couple of years ago (not knowing there were non-N rated SO2s available) and immediately realised something was very wrong with the handling when driving back from the fitter. I would go so far as to say they were bordering on dangerous when fitted to a 996. Felt like the sidewalls were nowhere near as stiff as N rated SO2s. This incident highlighted the N rated issue to me. I can't say whether other tyres behave in the same way and I have seen a number of Boxsters and 911s fitted with non N rated tyres of various brands, with the owners seemingly happy with the handling. I've only ever had Michelin Pilot Sports, Sport Cups, SO2s and Dunlop Super Sport Race tyres fitted to my car and all have performed very well, although I'd say for all round wet/dry road use the N rated SO2s are a great all round tyre.