Anyone know what the difference is for an N rated tire?

I always thought it was code for a stiffer sidewall to deal with the extreme weight (and yaw) of the 911. But that only makes sense in the rear.

Why does one need an N rated tire in the front?

 

I think you talking about the porsche factory tested and approved tire rating like N0, N2, N3. This indicates that the tire was developed in cooperation with the factory. Never mix number like N0 and N3... Other car manufacturer approved tires like this as well.

 

I believe that these designators can range from nothing, to minor tread differences for road noise, to real construction differences, ... to a business deal that allows the tire mfg to leverage a rating for higher sale price in exchange for a 'deal' on tires for the mfg when they purchased the tires OE.

It depends on the tire and the marque.

 

+1

"Porsche N-Specification Tire Approvals"


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.

 

Call me a skeptic, but unless I know what is different about the tire to cause it to have an "Nx" spec, I suspect it isn't that great. I do agree that you do not want to mix specs on an axle.

While one cannot argue with this 'marketing piece' since we do not know the underlying construction details, it is designed to keep Porsche owners buying N tires forever. (as it does for BMW, Mercedes, etc, etc)

If there is an independent third (unconflicted) source for tire details, I'd love to read it...tirerack isn't one either.

A

 

Here is an interesting link, don't know why you don't think Tirerack's information is unacceptable?

Tirerack N-rated tires

 

Interesting read. But it kind of makes my point...

".. and their exact design specifics are considered proprietary and confidential. Therefore, Michelin was unable to provide any details on the functional differences ..."


This post is really here nor there. Sure the tires are different- sure they cannot be mixed. If you are racing only on dry tracks, which tire is 'better'? Did the Porsche engineers trade off dry traction to improve hydroplaning resistance to avoid lawsuits from owners that run MPSCs in torrential downpours? Maybe they spec'd just a slight 5 degree difference in the rubber compound glass transition temperature - and traded off wear or traction (but still enough to have the same wear rating)..who knows?

My point is that there is no way to know WHAT the N spec really means... sure sounds like we all ought to only use Nspec tires since they are matched to the car... but remember, porsche has a lot of other criteria that may go into this process.

Tirerack is conflicted- they will never say anything against any tire mfg. In this instance they simply present differences- without any rationale other than the hydroplaning. I do note that POSTS from Luke, Damon, et al are different that stuff they put on their website... as individuals they have a bit more latitude than their corporate website allows.

Finally, I'm just taking a 'contra' approach here.... a discussion on both sides of this issue as opposed to blindly following a recommendation that MAY be based on $ and/or designing tires for driving conditions the car will never see.

A

 

That Michelin "N" rated tire looks like it will do better in the wet and do worse in the dry. Visually they have simply widened and and added more rain grooves and removed contact patch. Give me the NON N rated Pilot Cups any day....

 

personally..I could care less about N-rated..get the tire that works best for you..I am currently a fan of Yoko's...I used to have the 008's but they were discontinued...the Neovas look great...too bad I can't gat them in 19"

 

I beg to differ.

There is a big difference between N and the non N designated tyre. I’ve had Bridgestone S02 Potenza Pole Position (a non N version) on my Porsche 944TS once and they were terrible. Car became a chewing gum, soft and horrible handling. I couldn’t wait to wear them out and junk them. I rang Bridgestone as I was concerned and was told that I have been sold the wrong tyre type and that the N version has stiffer sidewalls designed specifically not to ruin the handling characteristics of Porsche. Apparently 944’s are really sensitive to this. I now always use N designators for my P car.

 

Huh? I don't think N-rated tires were designed with front-engined cars in mind. What makes a 944 any different from a BMW? Nothing special about a front-engine Porsche.

 

This issue has been beat to death here and I have posted much on it. Do a search and much will come up.

If you would like to call me to discuss, please feel free.