RE "N" spec. O.K. look at it this way ABC motors is coming out with a new high end model. One of the
selling points is to be that it is the quietest car on the road. The bid goes out to the various tire vendors
to come up with the quietest tire they can engineer in a fairly common size, speed rating & fuel mileage
expectation. Tire company Z takes an inline production product, modifies the compound, tweeks the tread
pattern and comes up with a winning tire except for the fact that because of a compound change the tire gets 10
less wear than the inline production product. But thats o.k. since most o.e. tires do not carry a mileage warranty.
In the tire catalog the o.e. spec will carry a special part number signifying that this is the exact same tire that
came on the vehicle from the factory. In order for the tire company to commit to building a special tire the vehicle
manufacturer commits to a very large number of spec or in the case of Porsche "N" tires. This is not to say the o.e.
tire is any better or worse than the spec tire. It is however tuned to the specific vehicle.
-tom
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