N Rated tyres, are they needed?
 

Hi

Sorry to sound like a pikey but i recently bought 2 new tyres for my boxster which had good ratings and were a mid range brand. They were half the price of the michellin pilots that were on it but the company that i purchased them from said they had to be N rated as its a porsche. I had bought these tyres for my s2000 2 years before and they were great but not N rated even though the S2000 was faster and had better brakes. Just wondering of anyones thoughts on this. Its a 98 so its not under warrenty as i know it can effect this but not sure about the insurance side. Thanks guys

In my opinion, the "N-rating" is not really needed...

What kind of tires are they?

Porsche puts N rating on the tires of the tire companies they are in bed with. If they don't have some sort of contract with a tire company then they don't recommend their tires. In my opinion most of the N rated tires are over-priced and don't deliver the kind of performance available from several non N rated tires.

only other reason I can think of for having N rated tires is if your car is still under factory warranty... just speculating.

Whatever you decide, don't have mixed tires mounted on your car.

Porsche believes that tires are too important to their cars' performance to not have a say in the tires. You'll notice in the tire TSB that the manufacturers do not have a blanket N rating for all their tires.

That said, the manufacturers that do not work with Porsche on their tires could well have as good or better tires than those that do and that have N ratings.

The ratings change periodically and some drop off the list while others are updated as N1, N2, etc.

The design of a tire for a front wheel drive/front weight biased car could logically not work as well as for a rear drive/rear weight biased car.

You also must have a tire rated for the top speed of your vehicle, at least at time of manufacture.

Tire Rack is a good place to do research even if you buy elsewhere. Both their own testing & ratings and user reviews.

I think top speed is the point worth arguing. If I had occasion to drive my 986 at 150+ mph, I might be more inclined toward N-rated tires. Since my driving is principally on the road, with occasional autocross, I don't buy N-rated tires.

Something I read in the past indicated that N rating helped Porsche ensure consistency - some brands would change the formulation of the tires without changing the model number, and then when owners went to replace just their rears, the car would no longer handle properly.

-james

Regarding the insurance question, I ran into this years ago when I was buying tires for my 1994 Cobra that came with Z rated tires. The tire store told me that my insurance company would not allow me to replace the tires that were not rated for 150 mph and would cancelled my policy. Being the inquiring person that I am, I called my insurance agent that told me that they did not have any such requirement and if they caufght me going 150 mph they would cancell my policy. Needless to say I did not return to that tire store.

My mechanic at the dealer said the N-rated tires have to go through more QA processes than the same non-N-rated tires from the manufacturer. I've also read that the N-rated tires may have stiffer sidewalls than their non-N-rated counterparts.

Not all N-rated tires are high speed. The N-rated tires that came on my Cayenne only have a "V" speed rating (only good up to 150 MPH); they are rated for mud and snow. The summer rated tires that are N-rated are good for higher speeds ("Z" rating)

All I'm going to say is if you have N rated summer tires on your Porsche now, you could be doing better if you value high performance. The best summer tires out on the market right now do not have N ratings.

i have teh sumitomo htz II on mine and i saved a lot of money.