Mixing N rated tyres

[j7agy]

Hi all, is there any harm in mixing n rated tyres between front and rear axle. I have Michelin Pilot Sport 2 N3 on front and found a set of Michelin Pilot Sport 2 N4 for the rear. The N3 are available but more expensive. Is it an issue to mix? Thanks, John

 

[pattersonoxford]

Porsche and all of the N rated tyre manufacturers advise using the same tyre brand and N rating on all four corners. I endeavour to do so on my 996. God only knows (as the Beach Boys say) if it would make any difference mixing N3s with N4s.

 

[Rodney Naghar]

I can't imagine you'll be able to tell the difference. Even Porsche at times have allowed it (I have the TSB somewhere to prove it). Go for it

 

[Andyvvc]

I defy anybody to find an actual document that explains what the N rating means AND what difference there is between an N3 or N4 tyre of the same brand and version for example. OPC couldn't tell me. My local Indy could only postulate. We couldn't find N2 rated PZERO for the rear of my 996 to match the fronts anywhere. . . . All replaced by N4 which suggests my N2s from last year were a fluke that were in stock when everywhere else was selling N3 versions. We compared my old PZERO rears (N2) with the new N4 version. Nowt at all that we could see different except a different location of the PZERO sidewall logo!

 

[tscaptain]

Just because you can't see a difference externally doesn't mean much....[]

http://flatsixes.com/pors...l-when-choosing-tires/

 

[Andyvvc]

That's an unofficial chunk of Internet hyperbole isn't it? Do you or anyone else have a link to an official Porsche Tech document that actually identifies why an N3 has become an N4 rated tyre? Surely if there was a serious risk porsche would clearly outline what has caused a change in N rating numbers? Do any other performance car makers have a similar numbering system?

As and when I see something official from Porsche that explains the N differences I will be inclined to care. OPC, Independents and most of us being utterly confused by the significance (or lack of) when the N rating changes really doesn't add credence to porsche N rating changes.

Let's be clear. We all appreciate the N rating. Just not the difference between an N2 PZERO and an N3 etc . . .

That's an interesting article though tscaptain. Appreciate you posting it. I'd love someone from Porsche to qualify the N rating number changes . . . How significant does a tyre change need to be to warrant an N rating change?

 

[tscaptain]

The manufacturer says you shouldn't mix them. What you put on your own car is, of course, entirely up to you but I wouldn't tell someone else to ignore what the maker recommends

http://www.porsche.com/uk...porschecentreservices/

It may all be Internet "hyperbole" but, then again, so is some of this forum! Given that there is no cost difference I would always match them up if at all possible. That said it appears Michelin are particularly difficult to get hold of for a number of models at present.

I think Ferrari are the only other who have a numbering system, K1 K2 etc but could well be wrong!
It is odd that Bridgestone only have N0 and N1 for my turbo but I think Michelin are on the 4th variant!

We had an interesting presentation from Michelin man at a club night earlier in the year. It's quite mind boggling the number of components in a modern car tyre. He also said one shouldn't mix N numbers - and he was an engineer not a salesman!
I totally agree it would be most helpful if there was some clear explanation as to the changes in a tyre when a new N number comes along.

 

[Rodney Naghar]

That's an unofficial chunk of Internet hyperbole isn't it? Do you or anyone else have a link to an official Porsche Tech document that actually identifies why an N3 has become an N4 rated tyre? Surely if there was a serious risk porsche would clearly outline what has caused a change in N rating numbers? Do any other performance car makers have a similar numbering system?

As and when I see something official from Porsche that explains the N differences I will be inclined to care. OPC, Independents and most of us being utterly confused by the significance (or lack of) when the N rating changes really doesn't add credence to porsche N rating changes.

Let's be clear. We all appreciate the N rating. Just not the difference between an N2 PZERO and an N3 etc . . .

That's an interesting article though tscaptain. Appreciate you posting it. I'd love someone from Porsche to qualify the N rating number changes . . . How significant does a tyre change need to be to warrant an N rating change?

A quote from Jamie Mcwhir Michelin's UK technical Manager (taken from a thread on PH)



".....As the Technical Manager for Michelin in the UK, I will try and put this to bed once and for all, however this is highly unlikely...

N rating, or * BMW, MO Mercedes or K Ferrari, or similar is simply a homologation marking. What does that mean? Well quite simply the tyre has been approved by the manufacturer and very likely tweaked or tuned by the tyre manufacturer, in order to optimize the tyre and vehicle interaction. The easiest way of thinking of it is an off the peg suit (standard tyre) versus the bespoke suit (the tuned homologated tyre). Now as you are all discussing, while the standard suit will look right a bespoke suit will always be fitted just for you.

Hence the same applies to the tyres. Yes, you can use the non N rated tyre. Yes the standard super sport will work. We are in development for PS2 N rated replacement tyres at present which we are aiming for sept 2015 launch. So there will be something for owners of Boxsters, Caymans 996's & 997's with an N marking.Please don't ask me for specifics as I can't share more than that at this stage

What makes the approved tyres different? In the majority of cases its a tuning of the compound or construction (sometimes both) to make the tyres work better on the cars. I can't be more specific, as it really varies tyre to tyre. For Porsche it's tied into their warranty, but I do know than not all Porsche dealers enforce it the same way.

It's not a marketing con, and not a way to make more money. Believe me all tyre manufacturers aim to keep their product catalogue simple and less complex, from a production and logistics view. Having los of different variants of a tyre make life far from simple. However when we do tune a tyre for a vehicle it will make a difference to it's performance and that's what the manufacturers want for their cars and to some extent for the owners of the cars too.

So I hope that provides slightly more information, but feel free to ask me and if I can help I will

Jamie"

 

[924Srr27l]

I've seen and had this scenario come up many times and it's not an easy one to answer, but it should be.

Each N number is an evolution, a change in spec to warrant them designating a new superseded number, no doubt as tested on he Porsche test track.
I'm sure a Porsche dealership will advise all 4 tyres need to be the same number, it's the sensible and logical OPC answer.

I'm sure not many people would want to go on a track day with a Toyo R888 front set and a R888R rear set ?

However, for road use I've seen many Porsche's with mixed N numbers, especially when availability is poor or the number has been superseded
very often rear tyres are a higher number because the fronts are years old and have not worn out / been replaced.

The Michelin man doesn't say anything about not mixing other than each version is:
" its a tuning of the compound or construction (sometimes both)"

And as Andy mentioned :
"Surely if there was a serious risk porsche would clearly outline what has caused a change in N rating numbers?"

One thing I have noticed fitting Tyres for the last 9 years, is N rated tyres have less (Tyre run out) and are better balanced
(use less weights) than non N rated Tyres.

R

 

[oliver]

The 'N' spec question regularly arises and divides opinion.

I would normally go with the recommended 'N' spec options, in the same way that I keep my Porsches as original as possible and use my longstanding OPC to service them.

However, I do not personally believe it makes any noticeable difference whether the tyres are 'N' spec or not.

 

[Andyvvc]

I've re checked my tyres. Fronts are N2, rears K1. I'm typing this from a ditch just off the M1 []

Seriously though, I appreciate the links and quotes folks have added here. I would agree with the comment about some brands moving through N ratings far more rapidly than others. When I get home I will try to find a manufacturered date on my PZero tyres to see what age difference there is between the two N ratings. I'm almost certain that when I needed fronts early last year only N2 was about so they were purchased. Fast forward just one year to the purchase of the rears and N4 was then the 'current' version.

It's interesting to read the info from Michelin that was posted up, but also equally infuriating that even Michelin don't list what has changed between N ratings. That would certainly put the nail into any N rating concerns if Michelins website listed the changes between each N rated build/tuned tyre. The fact that the PS2 tyre wasn't N rated is also odd . . . I presume more to do with Porsche taking time to test and validate a tyre for N rating compliance rather than Michelin not knowing how to produce one? (The MPSS tyre is N rated already isn't it)

 

[924Srr27l]

However, I do not personally believe it makes any noticeable difference whether the tyres are 'N' spec or not.

That's another debate entirely ! (Do they make any performance difference?)

As much as you like to go to an OPC and not a great Indie for servicing, other people may also prefer to stick with Porsche's specific
recommended / tested tyres even though you suggest there's no difference, but you only fit them for originality.

I think it would be very unlikely that Porsche do not spend a lot of money & time extensively testing, recording and picking a compound
for their car's.
I also think it's unlikely the whole N rated thing is a scam money making scheme between Porsche and Tyre manufacturers?

I used to be sceptical many years ago, but I had some handling issues when pushing a 986 3.2S hard and when I tried a part worn Michelin PS2 N rated set the difference was staggering better, and this was after trying 2 other Non N branded tyre makes (Pirelli & Conti).

Since then (2005) I'm a fan and have convinced many other people since. all of which have noticed a difference and been very happy.

R

 

[Rodney Naghar]

I'm sure there are differences but they'll never be staggering. Your example isn't proof positive. I've used part worn N rates tyres on my old car and they literally pushed me into a barrier they were so off.

The only way to really tell is to swap sets straight after each other and do a direct comparison on track which I've never seen or heard of anyone doing.

On the road, I'd be amazed if anyone can tell the difference (mixing axles not on a single axle)

My policy is if you can get an N rated tyre do it, always match on a single axle. If you can't get the rears to match the fronts don't bin them, just get another (higher iteration) of the N rated tyres on the rear. Bar that, always go for a newer tyre (design wise then date of manufacture-wise) as that will always be better than a previous N iteration

 

[Lancerlot]

I once had a Carrera with Michis on the front and Contis on the rear - it was one of the best handling 911's I have driven. []
Of course it was frowned upon by my PC and wouldn't pass muster for extended warranty. []
BTW I don't think mixed 'N' ratings will pass at some Centres either!
Regards,

Clive

 

[Buddy]

Whenever I have replaced tyres I have either changed a full set or axle pair and managed to stay on the same N rating, Michelin have usually been the only manufacturer to have more than one N rating available in the market at any time. If warranty is an issue then best to stay with what the other axle has. Otherwise as for what the differences are I can't say but if the tread isn't different there must be a manufacturing difference such as a change of carcase or compound.

 

[j7agy]

Thanks everyone. Really appreciated. Based on the mixed feedback think I'll just stick to what I've ordered. In deciding I'm also considering the little mileage I do in the car and the fact its strictly road use. I always change the fronts and rears as pairs so they match, and had I realised before placing my order I would have matched per axle too, but can't imagine what difference they'll make between axles to go through the hassle of changing my order. If I get issues I'll update my post for everyone... costly experiment! Lol. Thanks again, John.

 

[richardjjs1]

Pirellis are available in N2, 3 and 4
N4 is recommended for Porsche!!

Been quoted 125.00 fitted for Front!!