TIRE for the 964 N OR NOT N
 

Quelle marque recommandez-vous en 255 40 R17 94 98 Y AND N OR NOT N

The N tire may have a slightly different compound or rear weight rating. Make sure the specs on that latter part are appropriate for a 911.
N says porsche has approved the tire. But many run non-N tires (myself included) with good results. N tires limit your options.

Was there an N-rating when the 964 was in production? Asking as I do not know but thought it was a newer thing.