N-rated or non N-rated tires?

With all the recent IMS threads, I figured I might as well start another topic that could devolve into a boobies thread: N versus non-N rated tires. I have done some searches (honestly) both here and on Google and haven't really seen anything that objectively describes the benefit of N-rated tires. What I've seen can be summarized as some version of: "N-rated tires are Porsche approved and you must use them", "they have a different formulation to non N-spec tires", "you have a Porsche, why are you scrimping on tires?" and "your warranty and/or insurance will be void if you don't use N-rated tires." Courtesy of the previous owner, my car has Sumitomos: 225/40-18 at the front and 285/30-18 at the back. They're OK in the dry and not great in the wet, which is an important consideration where I live. I may occasionally do some high-performance driving on a track, but by and large I'm on normal roads driving around and am unlikely to exceed 90mph. So with that in mind, what should I get? According to our friends at Tire Rack (who apparently supply Porsche NA dealers), I could spend anywhere from $500 for four Sumitomo HTR Z III (not N-rated) to $1200 for four Bridgestone Potenza S-02 A (N3-rated). The cheapest N-rated tires are the Pirelli P Zero Rosso at about $1000 for four. That's a big difference compared to the Sumitomos! Looking at the published specs on Tire Rack, I see that the Sumitomos have a 92Y service description (1389lbs, 186mph) and a UTQG of 300 AA A (3x standard tread life, >0.54g traction and able to run >115mph). The N-rated Pirellis do not indicate a service description other than being Z rated and a UTQG of 220 AA A (2.2x standard tread life, >0.54g traction and able to run >115mph). The non N-rated versions seem to have a service description of 92Y or 93Y, so comparable to the Sumitomos. From these specs then, there appears to be little difference between them. I've heard good things about the Continental ExtremeContact DW 92/93Y 340 AA A and they come in at $774 for four, and the Hankook Ventus R-S3 seem to be the new hotness but are apparently unavailable in the required size for the rear wheel(?). For the 225/40/-18, they have a service rating of 88W (1235lbs, 168mph) and a UTQG of 200 A A (2x standard tread life, >0.47g traction and able to run >115mph). Purely from these specs, they are "not as good" as either the Sumitomos or the Pirellis but realistically I am unlikely to exceed their limits!

The hankooks and sumis are decent for the $ but won't last as long or stay as sticky or quiet over the life as a higher quality tire. That is a lot of what you pay for. My favorite perf tire right now is the pilot SS which I have on my M5. Fantastic tire and consistent over the life which is pretty long for a summer perf tire. Also great in the wet. Not sure if those come in your size but worth a look. The Pirelli Pzero are good too. I've had those on a few cars and currently have the porsche spec version on 997 rims on my car. No complaints wet or dry on those either.

Doesn't really address OP's question, but I just did a related tire investigation and ended up going with Dunlop Direzzas based on this thread: https://rennlist.com/forums/996-foru...0-and-x51.html

I bought N rated tires because I researched it enough to become convinced it was important. N-rated tires have been tested and approved by Porsche for my 911, that's good enough for me.

I've looked too. No one says what goes into a Porsche approval. And the reality is that is does not matter. If it did, with all the Porsche's with non N tires, we would know. But with tires, you generally get what you pay for. If you look at the tests on tire rack - about the only place that actually compares tires, you will see faster lap times for the more expensive summer tires than the cheaper ones (again, generally).

Porsche approves certain tires for its vehicles, often because the tire manufacturer worked with Porsche to ensure the tires were suitable for the vehicle's weight and performance requirements. If you want to ensure that your service manager at the Porsche dealership continues to like you, or you prefer to not spend a lot of time researching tires, buy an N-rated tire. Regardless of the N rating, any tire that meets the load, speed, and size requirements for your vehicle can be used. For example, the Hankook Ventus V12 evo2 tires I am currently running are acceptable for the weight (load) of my 996, rated for speeds up to 186MPH, and are perfect for the conditions in which I drive (warm, dry asphalt). If you choose to explore the many non-N-rated tires that are out there that will fit your 996, make sure you understand the speed ratings for tires and the performance and load characteristics of your vehicle. You will hear that running non-N tires will void your warranty. I did not find this to be true with my 986 - the dealer didn't even attempt to use this bogus reasoning. Less scrupulous dealerships will often use this ploy to try to dodge warranty repairs. Learn about the Magnuson-Moss Warranty Act, which exists in part to prevent manufacturers/dealers from denying warranty claims for bogus reasons. You will hear that running non-N-rated tires will jeopardize your life. If you run a tire that meets all of the requirements for your vehicle, I do not believe you are more likely to die than if you're running an N-rated tire - assuming you're not driving maniacally. If you're running a non-N tire rated for 200mph AT 200mph and you drive into a cow, you are probably going to die, and it's probably not the tire's fault. If you are driving on a tire rated for 100MPH and the tire disintegrates after 15 minutes at 150MPH, this is your fault, not the tire's fault. You will hear that you are a sorry excuse for a Porsche owner if you "cheap out" and buy non-N-rated tires. If you give a quarter of a damn about what other people think about your purchasing decisions, you're a sheep and you deserve to live with the smaller selection and often higher prices associated with N-rated tires. You will hear that "you get what you pay for." Many factors go into the pricing of a tire, including the brand, the size, the popularity of the tire, the age of the design (sometimes newly released models are priced low to drive interest and initial adoption, and the prices increase once the hook is set). Sometimes tires become difficult to find and this scarcity drives the price up. And yes, sometimes the tire manufacturers gleefully rub their hands together as they gaze out over warehouses full of N-rated tires, knowing that MOST people are just going to buy the N-rated tire without a second thought. While it's not reasonable to assume that an ultra-high-performance "luxury car" tire is going to cost the same as a snow tire for a Ford Ranger, it's also unreasonable to assume that cost is the only metric by which you should evaluate which tire to buy. If you go online, read a bunch of glowing reviews for a specific tire from people with cars similar to yours, with similar applications to yours, and find that it meets all of your vehicle's requirements, you may have a compelling reason to try that tire. If, however, you're standing there looking at two heaps of tires, and you choose the one that's more expensive solely because it costs more, you deserve to pay more AND to be called names.

UTQG mileage rating (100,300etc) testing is performed by the manufacturer of the tire. (unless this has changed since the UTQG ratings started about 30 yrs ago) So it is decieving to compare mileage numbers between competing brands. Basic guideline comparing different models of same brand. Speed ratings you pointed out are almost irrelevant unless you plan to cruise at 130+ MPH for longer than 45 minutes on a hot day. Although the speed ratings do infer performance characteristics. I believe you would be most happy with Michelin Sport AS3 or Super Sports depending "weather" you drive in the rain often.

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Hankook and Sumitomo are not less than high quality tires, in fact Hankook has some of the higherst rated tires. They will stay "stickey" and perform better as long or longer than some more $$ tires. In tires higher $$ does not necessarily mean higher quality +1 I have Hankook V12's on my Boxster and love them. They are a great value and at or near the top in all performance categories for summer tires. The new version Evo2 is a 320 tread wear. I had Potenza SE-02 (N3) before and they perfiormed well, but tread life was crappy. The Hankooks are less than 2/3 the cost of teh SE-02's My 996 Targa has Michelin Pilot Sport A/S3's and frankly I don't like them. Great tread wear(500), all season and pretty good performance, but extremely noisy. When they need to be replaced I will probably put on the Hankook V12's. IMHO, Michelin tires are a bit overrated A lot depends on how you plan on using your car. If it is just street, you will want different tires than if you do a lot of AX and different again if you track your car As far as the N rated vs regular, I too could not find a definitive answer to the difference other than Porsche has approved specific tires for specific cars. What may be approved on a 996, may not be on a 986 or a 997 or 991, etc . Even an 18 may be approved but not a 17 or 19 Supposedly, there "may" be a difference in tread compounds or some secrete sauce. IMHO, I'm not concerned with N rating. I also understand that a Porsche dealer will not sell anything that is not approved for your car

The original tires of my car were the Michelin, I bought Sumitomo, is not my daily driver and I just cruise no autocross or track they have been working fine for me. Sent from my iPhone using Rennlist

Excellent reply by Schnelly. Wish there was some way to ensure that this info. comes up at the top of a tire search query.

I bought my car with N3 Continentals on the back (ZR rated) and none N versions of the exact same tire on the front (Z rated). My Porsche dealer would not balance my wheels with the non-N rated tires on the car. He told me that the 911 configuration of weight and driving characteristics has Porsche requiring specific qualities in their tires. The tread pattern may look exactly the same but compounds and belt design can be different between N rated and non-N tires. He did not tell me to change front tires...they were brand new and would be fine for normal street driving. However I am very fussy...so I found some N3 rated front tires and put them on. If I am driving aggressively...no track speeds but aggressively...I feel that there is a difference in the turn in between the two versions of the tires. That is my non-scientific personal experience. Porsche as a manufacturer has both its performance reputation and as well and legal responsibility to put together a package that delivers the maximum out of the car...and does so as safely as possible. We have all been drawn to these cars because of how the designers made them...for decades. I'm willing to go with their choice of tires.

For myself, I am not prepared to 2nd guess Porsche nor use my car as a test bed and use my money to try to expand the set of tires that are known to work on Porsches. When I test drove my Boxster before buying it I was quite happy with the way the car rode, steered, braked and just felt. I had no reason to when it came time to replace the tires to try non N-rated tires. So far with N-rated tires, every set of new rear tires or every set of new front and rear tires feels the same, even though sometimes I use different brands with different (sometimes higher, sometimes lower) N numbers. I have never mixed brands, nor even N-numbers. The same applies to my Turbo. Now of course a number of owners have strayed far afield regarding tires. And for the most part have not experienced major upset. At least they have not reported any. However, I note a few owners have admitted to the car not feeling right with non N-rated tires and going so far as to switch back to N-rated tires. This raises the question of are the owners who report "no problems" running non N-rated tires just not that tuned in to their car's handling, road feel, etc? Or are the owners who report problems just being nitpickers or have over active imaginations? Who knows? All I know is as I mentioned above so far with Pirelli or Michelin N-rated tires on my Boxster and either Continental or Bridgestone N-rated tires on my Turbo I have not had one moment where I wished for a different tire. (Well, except a few times when driving in snow with summer tires or when driving in rain on tires that I should have replaced beforehand.) While the N-rated tires are I'm sure more expensive than non N-rated tires the car always feels the same and behaves the same with the tires new or just before they are replaced and everywhere in between. This consistency in pefrormance, tire life, and what have you is worth something to me. So, it is up to you. Stick with N-rated, in fact just follow Porsche's rules/guidelines on this matter and essentially put tires out of your mind, or ignore Porsche's rules and guidelines and use what you want, what fits, hopefully tires with the same metrics as the N-rated tires, and possibly you can still put tires out of your mind. But you have to be prepared that if the non N-rated tires don't suit you or the car to possibly have to prematurely replace them.

Thanks for the sensible discussion. Schnelly put into words what I've been thinking. It seems that outside of Porsche engineers and the tire manufacturers, all we know is that we should go for N-rated tires because "Porsche knows best". Ultimately is down to us as individuals to make a choice, but I feel that using "Porsche knows best" reasoning would also imply that we would never replace oil sooner than Porsche's recommended service interval or replace the "lifetime" coolant. I will resist bringing up our favorite bearing...

If anyone is interested, here is the latest approved list (996 is on page 2) http://files2.porsche.com/filestore....5-001a64c55f5c I did not realize that the 18" rear wheel tires changed between the 996.1 and 996.2. According to this document, the rear tires for the 996.1 are 265/35ZR18, whereas for the 996.2 the changed to 285/30ZR18. The wheel size seems to be the same 10Jx18 ET65 though.

I tend to agree with Macster on this issue. The Porsche N rating is given to tires that have been tested by Porsche and that provide the performance characteristics that Porsche desires for the car. There may be other tires that deliver similar performance that haven't been tested and therefore aren't N rated. As a Porsche owner, you have to decide if you want to pay a premium for N rated tires and accept the Porsche performance standards, or if you want to choose another tire based on your own expectations for your car. For example, you may decide that you want to spend less money on tires. You may decide that you want a tire that offers longer tread wear life. These tires probably won't meet Porsche's standards, but they will meet yours. Porsche tries very hard to protect the brand image, and a big part of that is producing a car that delivers consistent performance. Tires can impact performance so much that Porsche decided to recommend a group of tires that deliver consistent performance. If you buy something that they don't recommend, then they can't guarantee the performance. So, that was my long-winded way of saying that buying tires that aren't N rated isn't necessarily a bad thing, it's just taking your chances with the way the car will handle. Some people will say that they can't tell the difference. Some people will say that they get better performance with a specific tire. If you don't want to try to find the right tire by trial and error, then buy N rated tires. If you are really comfortable with another tire, then buy that one. I've tried many tires on my Porsches (some N rated, some not) and I've never found a tire that I like better than the N rated Michelin Pilot Sport PS2. I will continue to buy them for now.

N Ratings are complete bull****. Go to any autocross on the planet and you'll see the top three fastest street tires are the Rival, Star Spec and the RS3v2 - they blow away any of the N Rated tires.

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We obviously have different experience with these tires. Compared to Michelin Pilot SS or PS2, the Hankooks and Sumi's both got louder as they wore and lost grip, in my experience at least on BMW's.

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The tough part for performance car manufacturers is that they have to balance cornering and grip performance with ride quality, tire noise and tread wear life. N rated tires perform well considering all these things. If your goal is pure performance and you're willing to compromise on some of the other things, then you're absolutely right. For some people, this is the right choice. For some people, it's not.

I'm sorry I can't hear you over the sound of my tire noise. In all fairness, these Hankook RS3v2s I've had on my RX-8 and 911 are phenomenal in the dry, quiet, and wear well - not so hot in the wet. The ZIIs I had on my 986 and 986S were good in the dry and the wet and the cold (I might have ran a 2 hour stint while it was snowing during an endurance race on a set), but they were loud and tramline really bad on the highway. All I know about the rival was the one time I drove on them they wouldn't behave unless you drove at insane slip angles like a complete moron.

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Go to any autocross on the planet and you will see cars using tires that are the best for that event...not necessarily for day to day driving or driving in rain or long life. The fastest cars are probably not running stock suspensions nor street brake set ups, and have usually had tons of other mods done to them. And those same set ups would change if your were running at the combination of speeds and heat tempretures of a full race track or autobahn. Porsche doesn't rate tires for their track use but for their road use by drivers of a variety of skills. The specifics of the 991 are very different from Boxster/Caymans or from RX8s or S2000s or BMWs. The transfers of weight in the 911 are and have always been unique to the car. Porsche wants the tires that are put on the car for real world use to be designed to work with the car's gestalt.

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The most popular autocross class is stock cars running 200tw street tires.

In '99 when my car was new N rated meant something. Fifteen years later tire technology has evolved and there are now non N rated tires that perform better.

For my non-track driving at highway speeds in temperatures from negative F to 115 I am quite satisfied with my Continental DWS - non-N rated tires. I got at least 30,000 miles on the rear set and the front two still have 50% tread remaining. From what I've read this is very good tire wear for the rears. Would I want these on my car if I was on a track or running canyons? No, No and No. They are sloppy in the curves and on the track. But in general freeway driving at 80 to 85 MPH (and faster) they are fine. The DWS is a comfortable tire and performs well in rain, light snow and on poor road surface conditions. For my winter driving in the Colorado Rockies I have a set of Blizzak LM 60s. Again, for my purposes they are fine. Both sets offer a much more compliant and quiet ride compared to the N-Rated Michelin Pilot Sports that were on the car when I purchased as a CPO. I got rid of them because they simply were not ideal on the poor LA area freeways that I frequent. So, I guess it all depends on where and how you intend to drive your car. If you are a daily driver in need of good all around ride comfort and wet weather prowess, I highly recommend the Continentals. Track and aggressive canyon driving go N rated or good High Performance Tires (check TireRack for reviews).

I was under the impression that N-Rated tires had some design features that favored a rear weight biased car. But that could just be nonsense. I've run the gamut, from Michelins to Sumis on a variety of performance cars and Porsche's. I favored Contis for a long time, but then put DWs on the 996 and hated them from the first minute. They are just about done and I'm thinking Sumitomo HTRZIII, mostly for the cost. That said, I just put Michelins on my wife's 330 cabrio. Bottom line: At some point you have to decide. Michelins are usually the best option if price is no object, though there are lots of other good, if slightly less capable tires. What's in your wallet?

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And I suppose you also believe in the tooth fairy, right?

The tires Porsche recommends are for the cars as they come from the factory. If you modify the suspension, change wheel size, add spacers, etc, you alter the design peramiters Porsche created and it is logical the way the tires respond will be altered. All you have to do is watch F1 to see ten teams and 20 cars and drivers, all using the exact same tires and with various results in terms of wear and handling. Talking about how a specific tire works on a Mercedes or BMW or an RX8 or a Corvette has nothing to do with how they will perform on a 911.

As most p-car owners know, Porsche lists specific performance levels including top speed in their owner manuals, something I have never seen in any other car manuals. But as many p-car owners might not know, Germany has some of the toughest product liability laws in the world. (Their "green laws" are also very tough.) Hence, if your owner's manual says your model has a top speed of 174 mph, then Porsche makes sure they test and specify tires capable of supporting that claim. On this point, the engineers and lawyers appear to have worked in tandem. relinuca

Further proof that Porsche can slap their name on anything and sell it for double the price...... Do you really think that Porsche tests a new N-spec tire model on EVERY past model? Do you really think that tire manufacturers create a special model of an existing tire for a super low volume manufacturer like Porsche, and said tire is superior to every other similar tire they make? It's marketing, pure and simple. Porsche tires from their OEM suppliers get an N-label, Porsche gets royalty payments, the tire company charges twice the price for a normal tire. Sure they meet Porsche specs, but speed ratings, tread wear, and load ratings aren't exactly rocket science. Tire Rack can show you a long list of tires that meet that your car's specifications in about 0.5 sec. I've had plenty of N and non-N rated tires on Porsches, probably my favorite balance of price and performance is the Potenza S04. I find them to be superior to the more expensive and N-rated RE050.

Luckily for us, all the tires without the N rating are evaluated and sold on purely objective criteria without any of that nasty "marketing" to influence the behavior of the buyer!

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Fortunately for us there's TONS of real world research and open information in the form of magazines (GRM and SportsCar's annual tire tests) along with the internet and forums. People who want to keep drinking the N-Rating Kool-Aid are fine to do that. Just like with a cult member, logic, reasoning, and the general rules of physics will not sway them. The rest of us will pay less money for tires that perform better and last longer based on informed decisions and real world experience. I literally can't even.

I agree, and I've always been open to trying different tires on my Porsches. I've tried cheap tires like Sumitomos and I've tried expensive options like Pirellis. Based on my personal experience, I haven't found a tire that I like better than the N rated Michelin Pilot Sport PS2. If I found something that I liked better, then I would buy that. I'm hearing good things about the Michelin Pilot Super Sport. For me personally, I don't mind spending more money to get the performance that I want and expect out of my car (in all facets of tire performance). I see nothing wrong with buying an N rated tire if it delivers the performance that the buyer wants.

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^^ THIS If I didn't already think I understand how Porsche works--highest margins in the industry, ridiculously low-equipped base model cars with insanely expensive options, etc--I might think there was some truth to it. But mostly I think Porsche is good at creating a need and filling it. See "Cayenne"... If I could even get anyone to agree on what makes an N-spec tire different, I might relent, but here we are still asking the question. It can't be the "rear engine car" thing, 'cause tires already have load ratings. Also, my car doesn't see the track or go above 100mph, so I'll take my chances with Sumitomo for half the price of a Michelin N-spec.

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Physics. It's the law.

In my unsubstantiated and frequently wrong opinion, buying N-rated tires is about the same as buying a new MAF sensor in a Porsche box. You can buy the same damn sensor in a Bosch box for what, half the price or less? If you WANT the parts that St. Porsche has blessed, then by all means buy the Porsche-blessed parts. If you believe as I do that one can properly maintain a Porsche without paying the Porsche parts tax, you too can delve into the dark art of non-N tires and white cardboard component boxes...

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...Panamera...Macan...

" Also, my car doesn't see the track or go above 100mph, so I'll take my chances with Sumitomo for half the price of a Michelin N-spec. " With that kind of usage why a Porsche in the first place? Anyhow, I hope you won't begrudge those of that do track or at least go above 100mph our N-rated tires.

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I'm sorry but that is not a compelling argument against using N-rated tires. There have been enough reports by owners who have elected to use OEM vs. OE hardware and regretted it that it is clear that straying away from genuine Porsche hardware is not without some risk.

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Can you elaborate on how Porsche creates a need??

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...and perhaps if I _ever_ experience any of that risk, I'll understand your willingness to pay extra for what I believe is often the exact same item with different packaging - or perhaps an "n" added to the mold. I believe that the tire manufacturers agree to keep making a specific tire as-tested, and the N-rating is your guarantee that the tire you're buying is the same configuration Porsche has tested. I have driven my Porsches on N-rated tires - Pirellis, in the case of my Boxster, and (I think) BFG on my 996 - and I found both tires inferior to the non-N tires I replaced them with. Macster, I appreciate your insistence in using what you believe to be the "correct" parts. I get it - you have ideals. I don't think you're wrong - I just happen to believe that there can often be more than one correct answer to a question.

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My car frequently sees 100+ mph, with occasional visits to much higher. However, the 186mph rating of my non-N tires has been sufficient - no F1-style delaminations or failures to date.

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Michelin only makes 1 N rated tire for the 991 & it's a winter tire. There are no N rated Super Sports. Hmm!

Check your tyre temperatures with a digital thermometer and you will learn a lot!

There are Porsche recommended tires that don't carry the N rating for some cars. If you speak with your dealer or look on renntech.org, you can find the list. It sounds like the 991 is one of those cars...

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And you thus become guilty of what Porsche is being accused of. Porsche is accused of not fully testing N-rated tires just kind of giving them a (pardon the expression) rubber stamp. Based on your very limited "testing" you extrapolate all other tires like the ones you use are ok, and you imply that in fact all non N-rated tires are suitable based on your experience with just one set. So far.

I switched from Michelin PS2s (N-rated) to Michelin Pilot Super Sports several years ago. The Michelin PSS are NOT N-rated but I'm convinced they are better than the PS2s in almost every way. I say almost because I'm not quite sure which tire handles better in heavy rain. My opinion is that N-rated means that Porche has tested the tires and they are a safe bet for "very good" tires. But it doesn't mean that they are the best. If you are risk-adverse and/or don't have the time or inclination to fully research the tires you want to use, then go with N-rated and you won't be disappointed. But there are non-N-rated tires that will be just as good or better. And there are (many?) non-N-rated tires that will be worse. I personally think it is great the Porsche works with tire manufacturers and approves specific tires. If nothing else it hopefully raises awareness and discussions like these. But I personally have no problems running non-N-rated tires on either the street or occasional DE day. Also IMO The same is mostly true for OE parts. Going with OE is a safe bet. But there may be alternatives that are either better quality or similar quality at a lower price. But finding them requires research and risk of being wrong. I replaced my water pump with OE but my coils are Bosch...and my IMS bearing is LN . Sorry that was meant as humour.

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I'm guilty of selecting a tire based on its ratings and using it as rated. I'm also guilt of suggesting that other people can do the same if they so choose. Porsche does not - and should not be expected to - test every configuration of tire, wheel, and car. I have tested a subset of Porsche's approved configurations and did not find them ideal for my purposes. I have no idea whether Porsche tests every model of N-rated tire. What I am confident about is that it does not benefit Porsche to endlessly test new tires from many manufacturers with 15-year-old cars, and thus the selection of tires blessed for use by Porsche for our cars is AT BEST a very limited, and likely stale, subset of suitable tires. I prefer to cast the net a little wider to see if the market offers a tire that provides a palatable combination of suitability, performance, durability, and cost beyond the subset of tires Porsche has identified. There is nothing wrong with you - or anyone - preferring to choose only from those tires Porsche has identified as suitable, but I also don't think choosing a non N-rated tire is heresy or any kind of statement about Porsche. I'm not entirely sure why you're charging this windmill, Macster. The question was posed: N-rated or non-N-rated tires, and I answered the question with an opinion. It's clear that you don't share my opinion - and I'm not insisting that you should.

Ya - I really think the key is that the 996 is a 15 year old car at this point, so whatever Porsche used to recommend back then is completely irrelevant today!! IMO

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Porsche updates their recommendations for tires, just like they do with approved oils. The lists aren't completely static as suggested below - but they certainly are not all-encompassing. Preferred/approved lists are inclusive, not exclusive - i.e. Porsche includes enough items to ensure that people can find a new tire or a quart of oil that is known to be compatible with the vehicle. The very nature of these lists means they are not definitive/exhaustive...they just need to be extensive enough to ensure that you can find a Porsche-approved oil or tire in your neck of the woods... As expected, this thread continues on, and on, and on...

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Such as?

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where you need to adjust pressure where you need camber whether you're under/over driving whether you need to spray the tires down between runs how weight transfer is affecting the available grip pyrometer is one of the best tools I've used.

To summarize what I think I've read so far: 1. For me, N vs non-N is unlikely to make a difference (based on my driving requirements) 2. There may or may not be a an actual physical difference between N and non-N tires but no one except the tire manufacturer really knows. 3. Tire threads are not quite as contentious as IMS threads.

Number three may be subject to debate.

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I'm waiting for kcattorney to weigh in with his pictorial contribution

Maybe using non N rated tires is really the culprit behind IMSB failures... Yeah... That's the ticket!

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The the solution is obvious. Drive on the bare wheels, because they are genuine Porsche! Actually I looked on Tire Rack out of curiosity, there is an N-spec summer and winter tire available in both 19" and 20" sizes for a standard 991. So the disciples won't go hungry....... Are you honestly suggesting that if a manufacturer introduces a new tire in 2014, Porsche will go back and test that tire on every possible prior model before they put their N stamp on it? I hate to break it to you, but Porsche quit caring about the 996 when they stopped rolling down the production line.

FWIW - I'm running on fairly new (third set of tires now) Michelin Pilot Super Sports non N rated by choice and I love them. Look, my 99 996 is sixteen years old and has 133,000+ miles. I drive around town, don't track or DE, barely get out on the highway and have only once ever broken 100mph in the car. Most of the time the car is just getting from point A to B to C during the day. I do care about quality, cost and durability. I made my choice and I'm very happy with it.

[QUOTE=BBA;12020678]The the solution is obvious. Drive on the bare wheels, because they are genuine Porsche! Actually I looked on Tire Rack out of curiosity, there is an N-spec summer and winter tire available in both 19" and 20" sizes for a standard 991. So the disciples won't go hungry....... Originally Posted by Byprodriver Michelin only makes 1 N rated tire for the 991 & it's a winter tire. There are no N rated Super Sports. Hmm! So I suppose Michelin has deceided to take the high road & not accept the "N" conspiracy profits!

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Indeed. I failed to do so at a rather aggressive track event, and this is my brand new N-rated P-zeros after two days (was an expensive lesson): .

The part of this that nobody has mentioned is the liability issue. I wonder if Porsche makes recommendations and that if somebody crashes one of their cars while driving on tires that weren't approved by Porsche, then this issue is used by Porsche to limit their liability. I don't know if that's the case or not, but in today's society you have to wonder... "We cannot stand behind this product because the owner wasn't following our clear recommendations..." I have no idea I'd this is the case or not... Just thinking. This isn't a statement for or against N rated tires, just an observation.

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I feel it's a pretty good observation, though....

Probably a valid point for a car under factory warrantee. But I don't thing a mfg carries any liability on a 15 year old car.

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Oooo, they didn't wear very well, did they?

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You'd have been fine with $500 Sumitomos

Yeah, nearly $2k down the toilet for those tires in two days. Oh well, at least I had a lot of fun.

My brother learned the same lesson with his Boxster with street tires, and he ended up buying a dedicated track car. It's a slippery slope!

I'll say! I'm trying to hunt down a beater-Boxster now to use as a dedicated track car. After the cost of replacing the blown motor in my 996, I think a dedicated track car is the way to go.

There are lots of good deals on 944s out there, and many of them already have a racing cage, racing seat and harness, etc.

Yeah, I've almost bought a couple 944s recently... may still go that route. I guess I'll wait and see what "bargain" deal pops up locally.

I miss my 944 turbo like crazy!!! Sold it to get the 996. I WILL have another one. This one will be a toy and not a DD. Even more raw then the last.

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Beats me! I'm not even sure this comment was supposed to be in this thread!

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I have been told that, in the UK, there may be insurance issues if you have an accident on non N rated tyres.

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Interesting. I've heard about possible insurance issues if you wreck your car in winter conditions while driving on summer tires, but I've never heard of anything like that regarding N spec tires.

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Not true. In the UK if the tyre is correctly sized and load-rated then insurance is valid. Extended warranty is where the issue arrives. Initial manufacturer's warranty cannot escape paying out if something fails and an unrelated non-Porsche product is on the vehicle, but an Extended warranty will NOT pay out if any third party or non-approved product has been used. i.e. in extremis if you have an aftermarket exhaust and the PDK box blows up then in the initial 3 years manufacturer's warranty you're covered (as even in the UK the law prohibits the manufacturer trying to sidestep), but after that you are not under the extended warranty (as the car is not compliant with the T&C of that warranty). To be fair, a few Porsche dealerships in the UK will be a little more flexible, but very few will accept a car onto the extended warranty scheme if it has non-approved products, including non N-rated rubber.

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In Switzerland if you have an accident in 'winter' conditions without winter tyres you may be considered automatically 'at fault', so I believe.

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RJKflyer- Jeez, it's spelled "tires". Learn English will ya! Sorry boys, I just read this thread for the first time. Gotta agree with Schnell on this one, but what do I know - I'm just the boobies guy. And, here ya go!

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Bleedin' 'eck nice bristols.

From the manual. This makes me think N-rated is more of a liability issue than anything else. Tire replacements If in doubt, contact your Porsche dealer. Use only tire makes and types approved by Porsche. If you do not use a Porsche recommended replacement tire, make sure that you purchase your new tires from a reputable tire dealer and that the dealer complies with all manufacturers warnings for those tires.