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Porsche 'N' Rated Tyres Explained and Options

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The N Specification is a Porsche system of approved tyres, first introduced in the 1988 Model Year – it means that Porsche have worked with the manufacturer to produce an optimal road tyre for a particular model and wheel size combination, and tested it to their satisfaction at the time.

Whenever this process is performed for an individual set of approved tyres, the N spec number will increase. Often this will coincide with a model change, but can certainly occur within a model's lifetime, and thus a bewildering chart of approved wheel and tyre combinations (for summer and winter use) is produced and published twice a year in Christophorus, the Porsche company magazine, and in TSBs issued to OPCs.

Importantly, Porsche recommendation is matching brand, type and correct N spec ALL ROUND, however you can mix "the same N rated Tyre Brand on different axles Only" See the next post below for more details.

Since the first N rated list was produced subsequently updated TSBs have been issued, updating the list. N rated Tyres are a recommendation and not mandatory for Insurance purposes, all cars need to have 'E' marked tyres.

Technical Service Bulletin Quote [TSB]

If new tyres are to be mounted or the tyres of one axle are to be replaced, tires of the same make, the same type and with the same specification code must always be used on each of the two axles. If tires are replaced on one axle only, the different tread depth from that on the other axle can cause a noticeable change in the familiar handling. This is especially the case if new tires are mounted on the rear axle.

This effect decreases with increasing tire mileage. When replacing a tire on an axle, make sure that the tread depth of the new tire does not differ from that of the other tire by more than 30 %. They are also rather proscriptive on getting a round result when fitting tyres. In order to optimize smoothness of rolling, it is appropriate - and necessary in individual cases - to mount the tire in a certain (favorable) position with respect to the wheel (matching).

Matching (uncontrolled and controlled) is explained below:

Uncontrolled matching: Turning the tire on the wheel by 900 or 1200 if necessary in order to achieve an acceptable value with regard to rolling smoothness (true running, imbalance and weight distribution of balance weights).

Controlled matching: With a balancing machine with matching program. In most cases, this produces an even better result with regard to the rolling smoothness (true running, imbalance and weight distribution of the balance weights) than can be achieved with uncontrolled matching.

UK

Not all manufacturers produce (or did produce) all sizes, and for the UK, winter recommendations are ignored, which are aimed towards countries with mandatory European winter driving regulations.

Manufacturers continue to produce the same sizes in multiple N specs on the latest Porsche cars, although sometimes you have to search hard to get the correct one. Higher (and some lower) N spec tyres will not have been tested on older cars, although will work as well.

Same non-N rated tyre

Sometimes manufacturers produce identical size / models with and without the N rating. The N spec tyre will be different in some way, compound, tread grooves, sidewall construction, whatever, but it may not be apparent.

Porsche did all this testing for performance reasons, to ensure your car handled the way the factory intended, there are good guidelines here to follow. If you change sizes at all, you (are on your own and) need to be aware of the change in the ratio of front to rear rolling diameters, because a significant change will adjust the ABS and/or the 4WD.

The logical calculation of rolling diameter from the tyre section / profile is not accurate in this regard, so be warned, you may need to check with the manufacturer.

The same tyres in different sizes are often at different N specs, which is a totally normal stage of the tyre development process.

tyresize.gif
 

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Porsche information leaflet explaining the N-Spec approved tyres:

Design and Testing
Porsche designs and manufactures some of the highest performance vehicles in the world. Because of the essential role that tyres play in vehicle performance, Porsche has integrated tyres in the design process throughout vehicle development. Porsche original equipment tyres must successfully pass the tyre company's laboratory tests, road tests and race track evaluations to confirm that the prototype tyres meet Porsche's noise, hydroplaning, handling and high-speed durability requirements. Only upon successful completion of these tests, will tyres be released for production.

Branded as N-Spec
Production tyres that have passed all of the tests and received Porsche's engineering department's release can be branded with an N-specification. The N-specification brandings include: N-0 (N-zero), N-1, N-2, N-3, N-4, N-5 or N-6.

These markings on a tyre's sidewall clearly and permanently identify them as approved by Porsche for their vehicles. The N-0 marking is assigned to the first approved version of a tyre design. As that design is refined externally or internally, the later significant evolutions will result in a new generation of the tyre to be branded with N-1, N-2, N-3, etc., in succession. When a completely new tyre design is approved, it receives the N-0 branding and the succession begins again.

Replacing N-Spec Tyres
If a vehicle was originally delivered with N-specification tyres that have been discontinued and are no longer available, it is recommended to replace all four tyres to a higher numeric N-specification design appropriate for that vehicle. In case of tyre damage such as cuts, punctures, cracks or sidewall bulges that cause a single tyre to be replaced for safety reasons, the remaining matching tyre on that axle must not exceed 30 percent wear. If the remaining tyre has more than 30 percent wear from new, it should also be replaced. This rule applies to all four tyres on all wheel drive vehicles. Handling inconsistencies may result if this is not done.

Mixing N-Spec Tyres
Use only tyre types tested by Porsche. Only tyres with the same manufacturer and with the same specification code (e.g. "N0", "N1" ...) should be mounted on the vehicle. Tyres should be replaced no less than in pairs on one axle at a time. Only tyres of the same tyre make and type must be used. Since many Porsche vehicles are fitted with different sized tyres on their front and rear axles, this requires matching the tyre brand, tyre name and N-specification front to rear.

While the tyre manufacturers may also build other tyres featuring the same name, size and speed rating as the N-specification tyres for non-Porsche applications, these tyres may not be branded with the Porsche N-specification because they do not share the same internal construction and/or tread compound ingredients as the N-specification tyres.

Running-in of New Tyres
Initially, new tyres do not offer their full traction. Drivers should therefore drive at moderate speeds during the first 60-100 miles (100-200 km). If new tyres are installed on only one axle, a noticeable change in handling occurs due to the different tread depth of the other tyres. This happens especially if only rear tyres are replaced. However, this condition disappears as new tyres are broken in. Drivers should adjust their driving style accordingly.

Tyre Aging
Additionally, even though only the world's highest performance tyres can earn the Porsche N-Spec approval, eventually all tyres will either wear out or age out. The chemical additives that make rubber elastic lose their effectiveness in the course of time and the rubber becomes brittle and cracks. Considering the performance capabilities of a Porsche, under no circumstances should tyres older than 6 years be used. Porsche dealers can recommend the most current replacement tyre options for your vehicle.

Tyre Selected for a Porsche N rated status?
The tyres selected for a Porsche are chosen based on the model (sports car or SUV)"š and the job the tyres are asked to do. The 997, 996, Boxster and Cayman S are examples of the world's finest exotic performance cars with some of the same capabilities found in previous generations of race cars.

For these vehicles Porsche selects Maximum Ultra High Performance Summer tyres from the world's leading tyre manufacturers: Bridgestone, Continental, Michelin, Pirelli and Yokohama.


Porsche OPC's assist in ensuring you have the correct Performance Tyres
Decades of engineering excellence and racing heritage are designed into each Porsche vehicle. All the technology and innovation has to work through the four small contact patches that allow the performance potential to be realised. Many vehicle owners forget these four critical performance points are so important to their driving expectations, pleasure and safety.

Your Porsche dealer can assist in selecting the correct N-Spec tyre for your vehicle. By installing Original Equipment N-Spec Porsche approved tyres, you will keep your Porsche safe, secure and operating as designed and continue to enjoy the Porsche experience for miles to come.


Latest Porsche N Rated Tyre Options

- Please click the following link to open the attached PDF for the latest Tyres approvals for your respective Porsche range. (file then can be saved to you pc as required)

- PDF FORMAT

- UPDATED FOR 2014


http://www.911uk.com/docs/Tyres2014-Porsche-991-997-987C-Cayenne-Panamera.pdf

http://www.911uk.com/docs/Tyres2013-Porsche-996-986.pdf

http://www.911uk.com/docs/Tyres2014-Porsche-Classic-911-Early-964-993.pdf
 

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Personal choice of course and some feel good about N rated tyres on their car(nothing wrong with that at all).

however.....

"The N spec tyre will be different in some way, compound, tread grooves, sidewall construction, whatever, but it may not be apparent."

"Whatever" and yes one has a "N" stamped on it, so does that qualify the above statement?

Are we to believe that Michelin have a little sub-factory somewhere churning out tyres with different compounds, tread patterns etc exclusively for Porsche customers......err I think not.

What I find interesting about Porsche's N rated marketing blurb is that they never actually tell us what the specific differences are for any variant(if any) vs vanilla tyres.

Veryon's, McLaren's and other sports/super cars etc run fine on same brand/model "vanilla" quality rubber.....so why not a 911?


http://forums.rennlist.com/rennforums/996-turbo-forum/218724-n-tire-rating-necessary-or-not.html
 
wizard993 said:
Personal choice of course and some feel good about N rated tyres on their car

I'm always firmly in the 'Porsche know best' camp but I wont be ripping off my 3 year old half-worn Bridgestone N3s just because they're not on the latest list for my specific car. :nooo:
 
As usual I am in complete agreement with Wizard. The whole thing is very cleverly worded to make you think the tyres are 'special', but they never actually state the differences....if there are any.

In checking with our Michelin engineering contacts, they confirmed what we already knew, that OE tires are developed in conjunction with the vehicle manufacturer, and their exact design specifics are considered proprietary and confidential. Therefore, Michelin was unable to provide any details on the functional differences


It's a shame, as the original idea of Porsche testing and then recommending the best tyres available at the time is a good one.

The current implication that other tyres are unsafe is very wrong IMO.
 
The current implication that other tyres are unsafe is very wrong IMO.[/quote]

It's called marketing FUD(Fear Uncertainty and Doubt)
 
I can get SAILUN ATREZZ ZS PLUS 225/45 R17 94 W for £48ea 3 x B rating :thumb:
 
Imagine the silence and then the click after zingers calls his OPC for a tyre approval blessing :floor:
 
Zingari said:
I can get SAILUN ATREZZ ZS PLUS 225/45 R17 94 W for £48ea 3 x B rating :thumb:

Think I've had some of them - nice tread pattern :thumb:
 

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wizard993 said:
"Whatever" and yes one has a "N" stamped on it, so does that qualify the above statement?

Are we to believe that Michelin have a little sub-factory somewhere churning out tyres with different compounds, tread patterns etc exclusively for Porsche customers......err I think not.

I don't know what special insights or knowledge you base your personal views on this topic on, but I just don't follow the logic of that statement at all.
Tyres approved by Porsche for use on its products have N numbers on them which have obviously come out of the negative form each tyre was moulded in before it was cured. The N numbers are not some "stamp" which could be applied post-production to a generic tyre model, as you appear to think.
Looking at the enlarged image shown above it is also quite clear that the "N1" designation is an integral part of the sidewall moulding tool, and not a replaceable insert in the tool which could be removed for manufacturing batches of the same tyre size and model for use on the products of other car manufacturers. This means that it is a dedicated tool used solely for making tyres tailored to Porsche's specs, and not also used for the non-N versions of that tyre.
Since tyres are generally produced in large factories in large or small batches, depending on market demand, why would it be necessary that "Michelin have a little sub-factory somewhere churning out tyres with different compounds, tread patterns etc exclusively for Porsche customers..."?
It is what they do routinely, leading to the batches sometimes being produced chronologically so far apart that it results in the well-known shortages of some sizes when available stocks do not cover market demand in the interim.
Since tyre makers have been known to use two different tread compounds on the inside and outside edges of the same asymmetric tyre, I don't know why it should be so implausible that different compounds should be used for different batches of tyres to satisfy the specifications of certain OEM customers. :dont know:
Since the tyres are produced in discrete batches of a given type and size, it is also not an insurmountable problem for the manufacturer to maintain different specs for the lay-up of the textile belts to satisfy the demands of individual OEM customers.

wizard993 said:
What I find interesting about Porsche's N rated marketing blurb is that they never actually tell us what the specific differences are for any variant(if any) vs vanilla tyres.
The development engineers responsible for speccing the tyres would not be interested in "marketing blurb", and would generally see no benefit in getting involved in unproductive discussions which are not relevant to progressing their own work.

wizard993 said:
Veryon's, McLaren's and other sports/super cars etc run fine on same brand/model "vanilla" quality rubber.....so why not a 911?

How many vanilla sports cars are there running around on the Veyron's vanilla tyres, which had to be specially developed to be up to carrying that car's weight at up to 400 km/h? In view of their cost, not too many, I suspect.
The Veyron's tyres will just not be as vanilla as you seem to think, otherwise Audi would not insist on sending a service technician and a set of new tyres to the scene when a Veyron owner expresses the desire to take his car to its maximum speed.
 
I'm very much with Red on this one.

Its easy to say its a con...without any fact or substantiation.

Its easy to say its just marketing blurb...it swings both ways on both ends of the market. And I've had extensive first hand experience during my career in big brand marketing to have a reasonable understanding of the marketing.

I see tyres all day everyday on all sorts of Porsche. I sell tyres. Lots.

Just because many OPC's have inflated tyre (or fitting) prices it doesn't mean all N rated for Porsche tyres carry a Porsche tax. Infact many N rated are cheaper than the non-N rated equivalent. It is supply and demand, and people like Michelin who are premium priced know that they consumers are price sensitive and could easily lose out to say Continental for the duration of a Porsche owners ownership duration. There is plenty of choice within the 'N' rated group of suppliers.

Could they make tyres cheaper, yes. How does any lesser known brand break in to the market? Price. No different to any company, not least Porsche for example you cant tell me that a 911 costs so much more to produce than a Cayman (a car which broke the pricing model as it was more expensive than its softop sibling the Boxster).

Continental own and produce Uniroyal (Rainsport 2 for example). Why the difference in price? Marketing.

The bare facts are that Porsche have set a specification which they want tyres to confirm to. That's what N rated means. Approved for the car. Its amazing how across all sorts of cars how many people tell me they changed tyres away from approved and found the car to be undriveable, switched back and all probs they experienced disappear, particularly larger cars and SUVs.

Does N rating make them a guaranteed cracking tyre? NO, not at all. Pirelli seem to be all over the shop, the latest PZero's on Porsche seem to have bizarrely odd uneven wear characteristics. You just have to look at the issues from F1 they have to see how easily they influence the cars (and can get it wrong).

Are N rated tyres just the same as non-N rated but with an extra mark? NO, not at all in most cases. The overall load and speed rating is key here, but they can and do vary physically and dimensionally FACT. (Look at the below pic).

Also, you see variation in features like rim protectors across Mercedes (MO), Audi (RO), and Porsche (N) rated tyres.

My final word is through my business I have pretty good feedback through my straw poll of customers based on their experiences, my variety of loan wheels, and their changing tyres. Its pretty clear, and why I personally advise going N rated in most instances for Porsche unless there is a substantive reason to deviate. Not least on 911's which are pretty unique in terms of the engine positioning and the effect this has on both front AND rear tyres.

A tyre sale is a tyre sale, it makes no financial difference to me or any other tyre retailer.

HTH.
:bye:
 
I'll just pick on two of your points :grin:

Chris W said:
Are N rated tyres just the same as non-N rated but with an extra mark? NO, not at all in most cases. The overall load and speed rating is key here, but they can and do vary physically and dimensionally FACT. (Look at the below pic).

Just because (I'm using my imagination as there is no photo) one tyre is different in appearance (N vs non-N) does NOT prove that all (or even any) N-rated tyres are different in construction or compounds (from their non-N-rated versions - edit for clarity!)

Chris W said:
Not least on 911's which are pretty unique in terms of the engine positioning and the effect this has on both front AND rear tyres.

So why is the same (for example) 265/35/18 N-rated tyre marketed as constructed specifically for the unique handling characteristics of the Boxster 986 (mid-engine) and the 993 AND the 996? All three are, according to Porsche, very different cars with weight in different places.

And yet the same tyre magically is designed for all three? :?:

Why don't Porsche just tell us what the differences are? Then we'd all buy N-rated :hand:
 
Red993C4 said:
wizard993 said:
What I find interesting about Porsche's N rated marketing blurb is that they never actually tell us what the specific differences are for any variant(if any) vs vanilla tyres.
The development engineers responsible for speccing the tyres would not be interested in "marketing blurb", and would generally see no benefit in getting involved in unproductive discussions which are not relevant to progressing their own work.

hmmmm ok the engineers don't care about marketing, but the marketing departments of Porsche/Mich/Conti/Pirelli certainly do.

Standing up and saying 'we don't care what you think, it's a secret between the manufacturers, so buy N-rated tyres or forfeit our warranty' is a very very wrong way of imposing business upon your customers.
 
orangecurry said:
I'll just pick on two of your points :grin:

Chris W said:
Are N rated tyres just the same as non-N rated but with an extra mark? NO, not at all in most cases. The overall load and speed rating is key here, but they can and do vary physically and dimensionally FACT. (Look at the below pic).

Just because (I'm using my imagination as there is no photo) one tyre is different in appearance does NOT prove that all (or even any) N-rated tyres are different in construction or compounds.

Chris W said:
Not least on 911's which are pretty unique in terms of the engine positioning and the effect this has on both front AND rear tyres.

So why is the same (for example) 265/35/18 N-rated tyre marketed as constructed specifically for the unique handling characteristics of the Boxster 986 (mid-engine) and the 993 AND the 996? All three are, according to Porsche, very different cars with weight in different places.

And yet the same tyre magically is designed for all three? :?:

Why don't Porsche just tell us what the differences are? Then we'd all buy N-rated :hand:

I think you are using the power of suggestive thought, in order words reading what YOU want what I write to read :)

I cant find the pic the pic I was after in my library but will do in due course once uploaded to host site.

I don't mention compound or construction. I purely mentioned load and speed rating, physical attributes like rim protectors as an obvious example, and of dimensional variations. Eg 235 35 19 is not the same size on old PZero Rosso and new PZero.

I don't think that Porsche do word their marketing blurb the way you suggest, I may be wrong.

However the general weight positioning of a 993 and 996 are arguably very similar, and a mid-engined Boxster still has a relatively light front end coupled with rear wheel drive versus say a Golf, hence why a 225 40 18 Michelin PS3 for a Golf has a load rating of 93 whereas the PS2 approved for use on a 993/996/986/996 has a load rating of 88.

There is no design rule that says X car has to have X tyre 'construction', what they are saying is the unique handling characteristics of each car have been matched to a criteria or list of demands of a tyre. They are NOT saying each tyre has been uniquely designed for each car.

The rating/approval system is an easy and simple way to ensure correct load and speed rated tyre for your Porsche, or other car. Fitting an XL rated tyre even of the same brand and model, i.e. a reinforced one could mean it doesn't turn in or brake the way it is intended to do. It's common sense, especially when you have rear wheel drive, different sizes front and rear so you can get the right spec, in contrast traditionally to most family saloons. And if you still think it doesn't make much difference consider how differently cars with rear wheel drive versus front wheel drive behave in snow....afterall they have 4 wheels and 2 are are driven.
 
I am not suggesting changing load indexes, speed ratings, variant/brand of tyre, widths or any other important aspects of the Porsche fitment. Fitting cheapo tyres on a 911 is really not an option for the majority of owners.

....but a variant of Bridgestone Potenza can often be EXACTLY the same as one with a N rating. There is NO difference in compound or structure, nor is an N rated tyre constructed on a different production line at Bridgestone, specifically/exclusively for Porsche's.

Do you agree?
 

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