N rated Tyres.....Is it a Con?

Guest · Nov 17, 2005

Hi All,

I have recently been chatting to a colleague of mine who has been in the tyre industry for some 20+ years including time with Formula 1 and it would appear that the N rating is not all its cracked up to be. Apparently to qualify for an N rating you must pass the following tests:

Wet Grip.(Including Braking)
Dry Grip. (Including Braking)
Mileage (Ability to do 6,000 miles)
Road Noise.

These tests are carried out in various countries in Europe and your required to pass all 4 to get an N rating. However some excellent tyres do not get the N rating due to purely failing on road noise, as this was the case with Yokohama in Switzerland as it would appear that some European countries like there tyres to be silent running. So in short why bother with the N rating? obviously you stick to the correct speed rating etc and brand name of tyre if you wish but you could get a better gripping tyre that is not N rated i.e Goodyear F1 or Toyo. Lets face it with the rumble of the flat 6 behind you at 70 MPH tyre road noise is insignificant[8D] after all Continental got an N rating and they are awful[

] strange that there German tho[8|]. We don't buy N rated oil or Petrol do we??? and if you have an accident does your insurance company refuse to pay out if your tyres are not N rated.....No is the answer.

So is the N rating all it's cracked up to be? or is it just a license to print money[8|]

Your Thoughts Pls

oliver · Nov 17, 2005

Exactly.

If Porsche have invested billions of euros developing their products, they are going to work alongside the major tyre manufacturers to ensure that any approved tyres optimise their cars' handling, grip, braking, comfort and noise characteristics. Why take a chance with something that is not approved?

'N' rated tyres are probably less relevant to older cars as they will not have been tested on the earlier models.

Sundeep · Nov 17, 2005

although as discussed before, Pete does have a valid point...

my car was tested and rated for tyres that are now out of date, sure I do use the right but current N rated tyres and always will, but the point being that if I put on the latest Goodyear F1 tyres that are not N rated, will my car fall off the road.. the answer is no... and Goodyear would happily support that view

however there is also an equally strong logic to use N rated tyres, although there is a strong corporate profit in all those N rated tyres, as the majority of major & serious tyre manfacturers produce Porsche specific N rated tyres then it is correct decision to stick to these tyres..

even though I use the latest Michelin Pilot Sport tyres that are tested and rated for the 996, which as we all know is a very different car to the 993 ! but then again I have no intention of using old technology in view of developments in tyre technology...

but in the same light, I don't see how this is so different to all those aftermarket suspension kits that are fitted to many of our cars that are not Porsche OEM, and please using such Insurance arguements (which IMHO is not very constructive) on tyres could also apply to suspension parts, etc if that was the case then the whole aftermarket industry might as well go home now ! then of course there are brake pads, brake discs, whatever next.... cupholders !

happy motoring
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burrow01 · Nov 17, 2005

Does anyone know what is included in these two tests - the content would be fairly critical I would have thought...

Wet Grip.(Including Braking)
Dry Grip. (Including Braking)

I'm sure they are not just a quick blat around a test track and a tick in the box

I know at least one manufacturer (Michelin? I cannot remember exactly) has a different tread pattern for the N rated model of it's tyre.

We don't buy N rated oil or Petrol

No, but we do buy Oil specifically recommended by the manufacturer, and Optimax [

]

Regarding the usage of N rated tyres on older Porsches, how far back do the recommendations go - are 993's it?

I have always used N rated tyres - Pirelli and Continentals - on my 86 911, on the basis that they have been tested by Porsche engineers for use on a high speed sports car with a significant rear weight bias and similar aerodynamic characteristics (same basic shape!)

oliver · Nov 17, 2005

ORIGINAL: MoC2S

Bit less of the 'earlier models' stuff, purrleasse ..... !

cheers, Maurice [:-]

I was referring to the 15" wheel sizes, where the only 'N' rated tyres are Pirelli P6000s, which are not necessarily the best choice.

oceancarrera · Nov 17, 2005

All things being equal, I'd always go for an N rated tyre if possible just because. But I do think that there is some serious hyperbole regarding these in comparison to non-N rated tyres. After all, it's not like Porsches are either a) the torquiest/most powerful cars out there, b) capable of generating the highest cornering forces, or c) capable of storming down the automahn (or M1!) at the highest velocities that deserve "special" tyres compared to "normal" tyres as fitted to Fezzas, Lambos, TVRs, Nobles... heck, even Scoobarishis!... all of which can outperform many most Porsches on any given day in the hands of a skillful driver. ALL these high performance cars use "normal" tyres, and I certainly haven't heard of any "incidents" where their tyres failed to perform.

Point is: I don't doubt that Porsche did some kind of testing of tyres to achieve N-rating, but I suspect that this is as much of a marketing ploy than anything else - good for the tyre manufacturers to charge a premium, and good for Porsche to create a certain mystique. If a certain high performance tyre is good enough for an F430/Gallardo/T350/M3GTO/P1, then I suspect it would be good enough for a Porsche.

burrow01 · Nov 17, 2005

Anyone know what markup there would be for N rated as opposed to "Non N Rated" versions of the same tyre?

Guest · Nov 18, 2005

ORIGINAL: oceancarrera

- good for the tyre manufacturers to charge a premium, and good for Porsche to create a certain mystique.

good point just look at the price of Porsche bits![

] think Porsche got money[

] I am sure as soon as you pull up anywhere the cashier adds 10% to everything[

] look at the price of the plastic centre caps for example!! I will be considering Goodyear's for my next tyre change, I had them on the front of my previous 911 with Toyo's on the back............oh my god mixed tyres![

][

] this maybe BUT the handling was excellent especially in the wet which is what I wanted.

R

Mark_Bennett · Nov 18, 2005

ORIGINAL: oceancarrera

... "normal" tyres as fitted to Fezzas, Lambos, TVRs, Nobles... heck, even Scoobarishis!... ..... ALL these high performance cars use "normal" tyres, and I certainly haven't heard of any "incidents" where their tyres failed to perform.

Actually, Ferrari and Jaguar have special tyres made just for them ("F" and "J" tyres - just like our "n" tyres). So at least some other manufacturers also have "special" tyres.

danofesher · Nov 18, 2005

I've heard that 'N' rated tyres, especially those sizes designed for the rear of the car, may have stiffer sidewalls that a non N rated tyre in order to handle the high moving masses of the engine. I think you should always buy N rated tyres for cars built from 1988 (when the N rating was devised).

Guest · Nov 18, 2005

I just looked at my tyres Bridgestone Potenza SO2A, they are N3 rated.
The weight loading is indicated on the sidewall
Max load on the fronts is 560kg.
Max load on the rears is 750kg, and it says "Extra load".

Sidewalls are made from 2 rayon plies (tread from 1 steel, 1 rayon and 2 nylon).

Whether the fronts are any different from standard is unclear, but the rears are marked with "Extra load", so may be uprated to cope with the rear weight bias.

sawood12 · Nov 19, 2005

The test described in the first post sounds like a gross oversimplification of the tests that tyres have to undergo to achieve N rated status. It is not the case that the tyres are submitted to Porsche by the manufacturer for evaluation to get rubber stamped as N rated so they can then charge a higher price. The tyre engineers work with Porsche engineers before and during the tyre design and development over a long period of time with extensive track testing before the tyres earn their N rating. I'm sure that the nature of the tests is a closely guarded secret between Porsche and the manufacturers and anyone who hasn't worked on the collaboration and claims to know the details is purely waffling on about something they know nothing about. Porsche will be looking for a very distinctive tyre characteristics in order for the tyre to work with and compliment the suspension geometry design and spring and damper rates.

With the past few F1 seasons we've all seen how important tyres are when it comes to the overall performance of the car. You can have a competitive car but without good tyres you are nowhere (i.e. Ferrari). Porsche achieve excellence through attention to detail and you can bet your bottom dollar they pay alot of attention to detail on key components like tyres.

There are real differences with N rated tyres - stiffer sidewalls being just one, and they are all deliberate differences to enable the driver to get the best out of the car. I'm all for aftermarket products and parts but when it comes to the essentials - tyres, oil and brakes, I'm all for going with the OEM recommendations. And lets face it the cost difference between N rated tyres and non-N rated tyres is not that great - it's less than a tenner each on Contisports.

Even though the vast majority of us are not good enough drivers to really get the best out of any tyre unless you do alot of track work, you are better to have the proper kit than not.

Guest · Nov 24, 2005

ORIGINAL: Stuart Martin

I just looked at my tyres Bridgestone Potenza SO2A, they are N3 rated.
The weight loading is indicated on the sidewall
Max load on the fronts is 560kg.
Max load on the rears is 750kg, and it says "Extra load".

Sidewalls are made from 2 rayon plies (tread from 1 steel, 1 rayon and 2 nylon).

Whether the fronts are any different from standard is unclear, but the rears are marked with "Extra load", so may be uprated to cope with the rear weight bias.

I've just ordered the Bridges on N rating and was also in a dilemma on whether to order N or not to!!

I think the tyres are a vital part of the car and read considerable forums before ordering, to justify the premium [8|].
Surely the manfacturers must have some justification to stamp an N on their brand or their would be plenty of uproar by now?

I must admit that each time I drive my 993 Targa i fall deeper in love with her and its a tiptronic [:-]

Scott you make a valid point with the small costings as i'd rung around several places for prices and there was small differences.

Hi btw and this is my forst post [

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oceancarrera · Nov 27, 2005

ORIGINAL: sawood12
With the past few F1 seasons we've all seen how important tyres are when it comes to the overall performance of the car. You can have a competitive car but without good tyres you are nowhere (i.e. Ferrari). Porsche achieve excellence through attention to detail and you can bet your bottom dollar they pay alot of attention to detail on key components like tyres.

To equate F1 tyre dynamics and physical demands to street, heck even track!, usage on our beloved Porsches is exceptional over-exaggeration. The physical demands placed on tyres in a F1 race are so many times above what our cars will ever experience that comparison is futile.

If Porsche places such attention to detail on things like tyres, then why do our cars leave the factory with a randomly chosen set of Conti, Pirelli, Bridgestone, or Michelin tyres depending on whatever is available in stock? All of the factory tyres may be "N rated", but as several have testified, there are many differences between these four brands of tyre, and yet Porsche doesn't think it important enough to standardise on just one brand/model of tyre.

This all tells me that I the "N rating" is just a Porsche stamp of approval that recognises minimum quality/standards, but it does not necessarily mean that N-rated tyres are superior to other high end performance tyres.

FWIW, even Renault Meganes and Clios claim to have unique, purpose designed tyres from the likes of Michelin (the Pilot Exalto 2s). So either Michelin et al make incredibly poor tyres, as standard, forcing all car manufacturers to demand custom tyres, or we have all fallen for some brilliant marketing by those who do it for a living. Excuse my skepticism, but I really think the latter... when so many main stream car companies claim to have/require unique custom tyres for their "exotica", it does make you wonder if those tyres really are so unique after all... Will a Ferrari-rated tyre perform badly compared to a N-rated tyre?... I would be surprised if the difference were more than 1%...

sawood12 · Nov 27, 2005

Adrien, what you say is completely true in the same way that the vast majority of all Porsche owners and drivers only ever drive their cars to a fraction of what they are truly capable of but we still drive them instead of Meganes and Clio's. However it does not stop Porsche from designing and building these cars and doing a proper job of it in the process - which includes working with tyre companies to design bespoke tyres for their cars. It's a fact that Porsche does invest alot of time and money working with the tyre companies to develop N rated tyres so they must think they are getting some benefit from it even if it is only a benefit that can be unlocked by a hanful of people who really can drive the wheels off these cars. It is not simply a stamp of approval. I read an article in one of the magazines a couple of years ago (911 and Porsche world I think it was) which was talking about the development process that Dunlop were going through with Porsche in the development of thier first N rated tyre and it was no rubber stamping excercise that's for sure. I'm not saying that we all would know the difference between N rated and non-N rated tyres on our cars but I just think that for the minimal extra expense involved you might as well have them as not. We all look out for Porsche recommendations when it comes to things like oil, why not for one of the most fundamental and important bit of the car like tyres?

oceancarrera · Nov 27, 2005

Got to admit that I have fallen for some of the Porsche marketing, and would always go for Porsche-sanctioned recommendations when possible for peace of mind (unless proven and superior alternatives are recommended by those in the know... eg, Bilstein HDs...)... but I do think that there must be some element of truth in the title of this thread...

Cheers -

ps, I'll be looking for some N-rated S02As in Jan/Feb... has anyone here done the homework and found the cheapest supplier? [

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bobafett · Nov 27, 2005

Has anyone mentioned insurance, as im sure on your porker you are supposed to have Porsche approved tyres to be covered in the event of an accident.

I have to say i do feel there is money to be made in this field by tyre companies, as some of the evos and Scoobies i have owned have had some great tyres that grip like a tick, and no N in sight.

having said that with a Porsche its not a couple of grand rice packet your running around in, do the right thing you know it makes sence!

sawood12 · Nov 28, 2005

I don't think the whole point of the N rating is to do with safety - an N rated tyre is not more unsafe than a non-N rated tyre - it's more about maximising performance potential. I wouldn't guess that the insurance companies are that wise to the whole subject in the same way that you can fit re-moulds to any car even though they are sub-standard and you would be covered. But as with all insurance issues my advice would be to check with your insurance company and put your own mind at ease rather than taking the word of someone from this forum.