] How many miles have you covered with your present set? Regards, Clive.
Dan, whilst we all love a bit of warranty bashing [
] The N rating is nothing to do with warranty or extended in that sense.. Porsche specify that the N rated tyres will produce the characteristic handling of it's cars with the N rated tyres fitted anything else they do not suggest or recommend you fit. Whilst, Yes the OPC then do get all silly about keeping them N rated tyres, it is more the fact that you may be using tyres not 'recommended for use' on the said motor vehicle that the insurance and likes may be interested in... [&:] Although as pointed out the new 991 does come with the new tyre is is not an official tyre for the 997. Porsche are not the only manufacturer to use a system, many other high performance manufactureres do exactly the same.. At the end of the day though, you pays your money and take your chances. garyw
This isn't actually true. I've got a TSB showing just such a recommendation (2 different sets of N rated tyres - 1 on each axle) People get way too worked up about mixing N-rated tyres on their cars. Unless you're driving on the ragged edge on the road you're going to be hard pressed to notice the difference between iterations holding all other factors equal. If your OPC tells you you can't and that your warranty will be void, ask me and I'll send you the TSB proving otherwise.
Significantly different from Porsche's own statement then! Must admit I think I'll believe Stuttgart on this one, as if it was just an approved label and no changes needed to be made then they would get them out ASAP to get the revenue back in, and there would be no N1, N2, N3 etc. @Rodney: Interesting TSB, thanks for sharing. It's rather specific on exactly which N-versions of the PS2 can be mixed though, rather than a document giving carte blanche to mix and match at will. Not that that's what you were saying in the first place of course, just making a comment.
It's got to be a political holdup as I can tell you first hand that PSS handle brilliantly on my 997 - better than the PS2 did (although the PS2 are much lighter) - and many other 997 owners say that too. Maybe they are waiting for the last 997s to come off the production line - so that they dont have to re-certify them on PSS? I doubt 997s will ever be certified on PSS - it's too late now. Here's an article on n-rated tyres: Sports cars are often described as vehicles that "stick to the road." Sports car tires make a major contribution to this phenomenon. These tires are very complex products meeting numerous, largely contradictory demands. Finding the proper structure that balances these demands for any given application is the great challenge in tire design. Porsche designs and manufacturers some of the highest performance vehicles in the world. Because of the integral role that tires play in vehicle performance, Porsche has integrated tire development throughout their process of vehicle development. To be an Original Equipment tire provider on a Porsche vehicle or be approved by Porsche for the replacement market requires the joint product development efforts of the tire engineers working alongside the Porsche vehicle engineers. The focus in recent radial tire development for Porsche vehicles has primarily included optimum handling on dry surfaces and the safest possible behavior on wet surfaces, even at high speeds. Tires developed by various manufacturers, in concert with Porsche, offer a specific set of wet grip properties which few, if any, other automobile manufacturers demand in equal measure from the tires they use on their vehicles. Tires may be specified for a particular vehicle or range of vehicles and must successfully pass the tire company's laboratory tests to assure that they would be capable of adequately supporting the Porsche vehicle while allowing it to reach its top speed on the German Autobahn. Additional laboratory, test track and race track tests are conducted to confirm that the prototype tires meet Porsche's noise, hydroplaning and handling requirements. Prototype tires will also be evaluated to assess their high-speed durability, uniformity and serviceability. Upon test completion, the tires will be released for production. Production tires that have passed all of the tests and received the engineering department's release can be branded with an N-specification. The N-specification brandings include: N-0 (N-zero), N-1, N-2, N-3 or N-4. These markings on a tire's sidewall clearly identify them as approved by Porsche for their vehicles. The N-0 marking is assigned to the first approved version of a tire design. As that design is refined externally or internally, the later significant evolutions will result in a new generation of the tire to be branded with N-1, N-2, N-3, etc., in succession. When a completely new tire design is approved, it receives the N-0 branding and the succession begins again. It is recommended that only matching tires be used on Porsche vehicles. Since many Porsche vehicles are fitted with differently sized tires on their front and rear axles, this means matching the tire make, tire type and N-specification. If a vehicle was originally delivered with N-specification tires that have been discontinued and are no longer available, it is recommended to change all four tires to a higher numeric N-specification design appropriate for that vehicle. Mixed tire types are not permissible. It is also important to know that while Porsche N-specification tires have been fine tuned to meet the specific performance needs of Porsche vehicles, the tire manufacturers may also build other tires featuring the same name, size and speed rating as the N-specification tires for non-Porsche applications. These tires may not be branded with the Porsche N-specification because they do not share the same internal construction and/or tread compound ingredients as the N-specification tires. Using tires that are not N-specific is not recommended and mixing them with other N-specification tires is not permissible. Tires should be replaced no less than in pairs on one axle at a time. Only tires of the same tire make and type must be used. However, in case of tire damage such as cuts, punctures, cracks or sidewall bulges that cause a single tire to be replaced for safety reasons, the remaining matching tire on that axle must not exceed 30 percent wear. If the remaining tire has more than 30 percent wear from new, it should also be replaced. Handling inconsistencies may result if this is not done. Initially, new tires do not offer their full traction. Drivers should therefore drive at moderate speeds during the first 60-100 miles (100-200 km). If new tires are installed on only one axle, a noticeable change in handling occurs due to the different tread depth of the other tires. This happens especially if only rear tires are replaced. However, this condition disappears as new tires are broken in. Drivers should adjust their driving style accordingly. NOTE: The last two paragraphs are excerpts from recent Porsche vehicle owner's manuals.
Rodney, I'm sorry to have to disagree with you, but the literature is not conflicting as you suggest. All Porsche vehicle have to have the same make and N rating front and rear. The only exception is the 997 GT2RS, which has N1 on the front & N2 on the rears. This is because the way the car has been set up from the factory. Mixing manufacturers and/or N ratings can have adverse effects on the way the PSM system operates and the chassis handles. My local OPC has had customers in with specific PSM faults and handling problems due entirely the fitment of non N rated tyres or mismatched N ratings. When Porsche manufacture the car, they stipulate to the tyre manufacturer what compounds to use, hence the N rating. The only tyres approved for 997 Turbo S are Bridgestone Potenza N1, Michelin Pilot Sport N2 or Pirelli P-Zero N2 and it is quite wrong to recommend in this forum that an owner fits anything else - although, of course, he is free to do whatever he likes. On the question of Michelin Pilot SuperSport, the official word from Michelin today is as follows:- Our Ref 1-500517462 Dear Mr White Thank you for your enquiry about N rated Pilot Super Sports We are currently in the process of working with Porsche on the approval of the Pilot Super Sport and we are not yet in a position to say when the approval will be obtained, as it depends on many different factors. Therefore we do not have any dates for when we will have the N specification tyres available. Should you require any further assistance please contact us on 0845 366 1590 (UK & NI) or 0044 (0) 1782 401590 (ROI), quoting the reference number above. Regards Joanne Consumer Contact Team David I hope this clarifies the matter for you. Will be interested to learn what you have finally decided to fit in due course. Regards, Clive.
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