andrew911

What's the deal with the last 2 digets "N0", or "N1" or "N2"? Any difference? My rears are 255's with N0, and the fronts are 205's with N0. The fronts are the original tires, and they're getting a bit tired after 12 years- the rear tires were changed by the prior owner, with stock Michelins.

Can I put 205/50-17 N2's on the front with the N0's on the rear? What do these numbers mean? I did a few unsuccessful searches, although I can swear I remember people talking about these numbers some time ago on Rennlist....

Andrew

ian c - u.k

i remember something about n2's , you have to change all 4 ????

you cannot mix them , or something

andrew911

That's what the tire place was telling me (that Porsche recommends not mixing), but the tire shop is trying to find me "N0's"- the tire guy did say he didn't think he's be able to find the N0 tires however. I don't want to change all 4 tires, but may have to....

ACFOUR

Andrew,

See Adrian's book, page 285 or his discussion on tires on Johns 964 web site, for what the N-ratings mean. You can mix N-ratings, but shouldn't mix tire brands or types.

jimq

Dont know that i would be doing to much high speed driving on 12 year old tires! Might not hurt to change them all for safety sake if anything.

garrett376

The higher the N-number, the more recent the updated testing and approval by porsche for the tire. That's what I remember from something I read (I haven't had dinner yet, so I might be wrong...)

Bill Gregory

Porsche recommends that tires be no older than 6 years old. You should be OK as long as you have the same brand and model of tire, even if the Nx numbers are different.

andrew911

OK- thanks for the info.

jimq- I am definitely changing the front tires- just posting to see if I need 4 tires or 2. Believe it or not, last year when I bought the car I took it to the tire guy, and he said I was OK for another year- they surprisingly were not cracked or dry rotted- car lived mostly in the a garage in Florida, and had 13K miles on it when I bought it. But now that I've had the car a year, I'm going to change the tires.

The backs are newer and still seem to be fine, but are "n0's"- must have been replaced at some point, although I don't know when.

Cuppie

First -tyres over five years old should be replaced.

Second -this is according to a very knowledgable Michelin rep and test driver(Steve Dolby)in the UK, N ratings should NOT be mixed without consulting manufacturer. Some combinations have been tested.

Third -correct Garrett. NO's started in the '90's, N4 is the latest incarnation.

Mel

jimq

I shouldn't be talking about old tires! My 230 SL mercedes has tires older than that :-) It pretty much just takes a leisurly stroll around the neighborhood and close by the house at slow poke speeds. Has a type you cant get any more so as long as they look ok (always been garaged) guess I will keep them. 964 Go fast speed is a bit different.

andrew911

Well, I've heard many people say tires shouldn't be over 10 years old....5 years old..etc. , but I think it really depends on the atmosphere where the cars are stored- if its dry air, etc. I agree once it gets to 10+ years, time to change, but 5 seems too short to me- heck, the new tires could be sitting in some warehouse for 1-2 years, and that would be half the life

The tire guy I use is quite reputable, and he did a visual inspection of the tires last year. He knew I was only going to put 2-3K miles on the car in the next 12 months, and told me to wait a year. He said the moisture level of where the car was stored must have been optimal, as the tires and all rubber & engine belts looked like new & were original (like I said, except for the rear tires which had been replaced) Now 12 months later I'm ready to change them, as its making me nervous.

I'm thinking I'd be OK with the N2's up front with the N0's in the rear- why would it make a difference if it was the same exact tire? It would definitly be better than what I have now, with 12 year old tires in the front. When I get a chance, I'm going to zip over to John's web site to see Adrian's discussion.

Weather I get 2 or 4, I'm going to stick with the stock Michelin Pilot Sports, as I don't need 100% performance being as the car is a cab & I don't track the car, and being as I've heard several people complain about eventual noise levels and very quick wear of Pirelli's. I drove a BMW once that had "noisy" tires (I think they were Continentials), and sounded like the car had snow tires.