N numbers

I've seen this topic in past threads, but it has hit me this time so I am looking for the "current thinking" on the matched tire issue.

I hit a pothole and blew a bead on my right front. Pilot sport PS2's, N-1, original tire (2008 MY), 19" with 11,000 miles. Tread depth is between 6/32 and 7/32 which is just over the 30% wear mark. Seems like I need to at least replace both fronts according to the "rule book". My dilemma is with the rears. They of course are wearing faster and I was anticipating replacing them soon, possibly at the end of this season (I put on 5-6k miles/yr).

I will be purchasing through tirerack since my local indy installs for them frequently. The problem is that only the N-2 version is available now. So, I could potentially have N-2's on the front and N-1's (worn) on the rear. Porsche manual says mixed N type is a no-no. Dealer says probably not a problem. I can't see the reason to not mix and match. But, I am more concerned about the new fronts and "worn" rears from a handling standpoint. Replacing all 4 is a costly proposition, but I'll stomach it if need be.

Your thoughts?...

Current Love: 2008 RS60; 1st Love: 2001 base, triple black

the rears with same brand/type and N-rated tires as the front tires.

I've replaced worn rears and the fronts have been just fine and never noticed any problems. However, I've never mixed N numbers and I've never mixed brands or even types. I can't guarantee it but I suspect if you replace the fronts with new tires and even though the rears are close (5K miles) to needing replacement the car and you will be fine.

As I touched on above though, if the tire combo doesn't agree with the car or you, then you'll have to replace the rears before their time.

Sincerely,

MarcW.

in the same brand and type tire just mean that there was a change and the new tire design/compound was resubmitted for re-certification.

Consider your situation before you lost the front tire. Your fronts had lots more tread than the rears. So you must have been able to survive such a slight difference. I'd worry more about the deep tread on the fronts versus the shallow tread on the rears than I would about some little N-1 versus N-2 difference providing the tire tread designs were similar.

The aprox same cost alternative is to switch to another brand of tire that is cheaper and replace all 4.

As the fronts will have a much greater tread depth than the rears, you might get a false sense of security in the rain. The steering response might feel fine, but the rears could snap.

Minus 40 degrees... Is that Fahrenheit or Celsius?

Thanks, all good points. My biggest concern is the performance disparity between the new vs old fronts and rears. Will keep pondering...

Just learned that the wheel is bent also. Dealer and indy both say repairs are usually successful. Any experience with wheel repair?

This sucks! My driving season is even shorter than Guenter's and I miss it already!

Current Love: 2008 RS60; 1st Love: 2001 base, triple black

should still give you good service.

There will always be performance disparity between front and rear tires at different wear points in their service lives.

There is of course the risk -- always and no matter the tires' condition -- of driving too fast for the conditions and the tires could be called up to deliver more grip than they can and well, this can be serious. One can't always know when this situation might arise either. Accidents come without much warning.

Now many many car owners, me included, drive thousands and thousands of miles in most all kinds of weather without any incidents. However, and I'm sure I'm not alone, I always slow down in wet weather or in other marginal traction conditions and give my car more room between it and other cars on the road, regardless of the state of the tires: new or on the wear bars.

But you have expressed some concern so I think you know the right answer for your situation: Peace of mind and safety come first so if you are that concerned replace all 4 tires.

Wheel repair? Be careful about wheel repair. The factory manuals state that repairs to light alloy wheels are not supported if the repairs involve straightening or welding. Cast material when bent is compromised and even if it can be straightened will not have nearly the strength it had before.

As for welding...On another forum a new (used) car buyer posted pics of the wheels that came on his car. At least one wheel suffered a failure that was clearly due to a botched welding repair.

I can tell you it is hard enough to find a shop that can refinish these wheels right, let alone repair them even if one wanted to ignore Porsche on this matter and charge ahead and have a wheel repaired.

When my Turbo needed its right front wheel touched up from some scuffing it experienced (the wheel was not bend, or dented or had any other damage just some visible scuffing to the surface) the wheel was ruined by the refinish shop and a new wheel had to be fitted at a cost of around (IIRC) $1800. I didn't pay for this though. It was either the body shop that farmed out this wheel refinish job or the wheel refinish shop that paid for the new wheel.

And yes, you read right: $1800 for one right front wheel, Turbo hollow spoke. Light. Expensive. Oh man are they expensive.

Thus my advice would be to replace the damaged wheel in spite of what the dealer and the indy shop tell you. In fact I'm surprised the dealer is advising you the wheel can be repaired. This is as I mentioned above contrary to what Porsche has to say on wheel repairs.

Sincerely,

MarcW.

Minus 40 degrees... Is that Fahrenheit or Celsius?
Edited 1 time(s). Last edit at 06/01/2011 10:44PM by Laz. (view changes)