Here is what I just posted on this subject on another forum:
I bought my 996 (used) almost a year ago, and then spent a long time researching tire choices to replace the cheap ones it came with. The result was the recent mounting of a set of the Eagle F1 GS-D3's (18") you are considering. I couldn't be happier.
I do not track my car, either .... daily driver and highway trips with my wife. In addition to wet/dry traction, road noise was important to me, as the roar I was hearing from the original tires was not a pleasant way to cruise in a car I bought strictly for pleasure.
Consumer Reports, whom I consider to be neutral and reliable, rated the Eagle F1 very high for wet & dry traction .... a little lower for noise .... a good compromise.
N rating .... I don't consider to be a factor. By sheer chance, I was in Zuffenhausen and visited the big Porsche Zentrum dealer adjacent to the factory just prior to making my decision. A lengthy discussion with the staff there led me to understand that N-rating is an "after the fact blessing" of a tire, as opposed to the oft assumed sign of "made to order for Porsche".
A salesman went to a new car and pulled out the owner's manual. He pointed out that: (1) it only mentions N rating in the context of matching mounted sets of the same N-rating. (2) it specifically mentions buying non-Porsche recommended tires and simply reminds one to buy from a reputable dealer and adhere to the specified quality (speed, traction, wear, etc) ratings.
Bottom line of the discussion, the use of N-rated tires is not seen by Porsche as a requirement in any way. This has been skewed somewhat by a deal between Michelin and US Porsche dealers to have the dealers as exclusive outlets for some Michelin N-rated tires .... thus assuring a recommendation from the dealer that "you must use N-rated tire".
Lest anyone get the wrong idea. A set of Eagle F1's does not represent a savings when compared to Michelins, Bridgestone, etc. I paid well over $1000 for a set. Its about finding the right tire for your needs / preferences / driving style.
Ironically, the very first N-rated tire was a Goodyear.
I love my Eagles, and the quiet, very stable ride they have given me in high speed cruising and heavy traffic commuting.
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Another fan of this tire posted (in part):
I have had F1 GS-D3’s on my car since April. .... Over all I think these are great daily driver tires. Especially if driving in the rain is a factor.
I can not comment on ultimate dry grip as I have not had them on the track. There are some logical arguments that the tire may not offer the best ultimate grip because of the amount of rubber in contact with the surface in the contact patch because of the aggressive tread design….maybe so. However, in daily driving and aggressive street driving situations I have never thought I wanted or needed more grip.
In the wet the tires are in a word excellent. The grip is fantastic in the wet with rock solid stability which has caused me to completely forget what hydroplaning is or feels like.
....... I think the combination of wear and wet weather traction make them an excellent tire for daily and trip driving duties.
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Hope this info is useful,
Kim
2000 Cab