tlee

Hi Ya'll,

Been sampling various tires and wondered if anyone knows more about the porsche N rating for tires, ie

I am currently happiest with Conti Sport Contact 2(quality and price) , and the rear 255/40/17is "N" rated but the front's aren't ( I believe due to being a non-standard size for porsche fronts 225-45/17). I wonder if the N tires are any different from a company's normal offering. In Conti's case they offer an extra stiff version for "heavier cars" (designed specifically for the SAAB) but that version costs more than Michelin PS2, so the price seems no longer a good value. However nothing I could find in this size has an "N" rating. The regular Conti SC2 is the best price but the Michelins aren't much more and seem to be most people's favorites, yet they aren't "N" rated so any feedback appreciated...

docmirror

An N rated tire is suitable for continuious speeds up to 87MPH. For this type of car, I would suggest a higher rating such as V. N rating is about the average for 'mild performance' type tires. Now, if the rating is actually from "Porsche" I have no idea what it means.

Doc

tlee

In this case "N" is actually for porsche "approved" tires, Thanks!

Bill Ball

The speed rating for the ContiSport Contact 2 is at least Z (149+MPH), and many are W (168MPH) or Y (186MPH). Varies with size.

Porsche's N rating confuses things. You can read this and see if it makes any more sense. Not to me. I'm not sure when Porsche implemented this, but I've not seen anyone apply it to 928 tire selection.
http://www.tirerack.com/tires/tirete...currentpage=35

hacker-pschorr

These are the tires that came on the 997 18" wheels I purchased (OEM tires on the 997). I just completed my 2nd DE with these tires, 6 hours on Road Ameirca over Memorial weekend alone. Not only am I suprised by the grip on the track, they hardly show any wear & they are excellent in the rain. For those who know Road America, I'm holding about 70mph in the Carousel with these, and I know there was more speed to be had (still new at this).

Bill Ball

Yeah, same tire came on my 996 take offs and they seem to perform well enough.

tlee

I guess what I wondered, and maybe can find out from Continental is if the tires that are "n" rated have a different construction than their other tires in the same model/line. Like I said the rears do have the "n" designation and I'm assuming that all the tires of the same model ie SportContact2 would have the same construction, and the guy at Discount Tire thought the reason the fronts aren't "n" rated is the size 225/45/17 wasn't typically spec'd on the porsche (I believe 215's are the normal front tire size for the other porsche models.

Anyhooo! Thanks, they do seem quite good for the money and are really lasting well on the rear. I previously have quickly worn through Bridgestone's, Yokohama and Kumho and these (be sure to get SportContact2, not regular SportContact) have so far been great, and the tread design seems to be their attempt to copy Michelin Pilot Sport 2 which are possibly better but probably $200 per set additional.
Thanks! (Oh yeah the rears have N2 designation FWIW, good article Bill!)

docmirror

Sorry, I guess I didn't understand about 'Porsche" ratings. My bad.

Doc

Bill Ball

No apologies needed for not knowing irrelevant trivia. Has anybody here ever seriously considered using only Porsche "N" rated tires?

At the time Porsche initiated the specification system, it may have had some meaning as the tire speed ratings were inadequate. That has changed.
http://www.nichols.nu/tip493.htm

hacker-pschorr

YES!!!!

Last PCA meeting I was at (going on at least a year now) local tire dealer was there talking about tires, proper care, models etc...

More than a few people wanted to know why they should spend the extra money on Z-rated performance tires when they really never go over 80mph.

Same group insisted I was wrong that age plays an effect on tires - tread depth all you need to keep track of (or so they wanted to beleive). Thank goodness the tire guy backed me up (owner of the low mileage 944 with the original tires was not a happy camper at that point). I dunno, cutting corners on tires, oil, brake flushes etc.... go buy a Buick.

Bill Ball

It's supid to believe that age, especially when combined with sun exposure, has no affect on tires. Sure, those cracks in the sidewalls are just superficial! Still, the N rating system is vestigal and not at all helpful when it comes to 928s as the spec was last updated in 1998.

docmirror

Okay, Porsche has set up there own arbitrary rating system to match what we already have in the US. All tires are rated for not only load, but also for traction, tread wear and temperature. This seems to coorespond closely to what ratings Porsche uses in it "N" system.

Always love obscure trivia! Now I wonder if there is a conversion chart for Porsche N values to the US system of A, B, and C for ratings of traction and temp, and the treadwear system of 0-1000 for compound?

Doc

jon928se

N Ratings as someone pointed out are largely irrelevant for a 928 as Porsche last updated 928 specs in '98. You can't buy 1998 tyres today (well you can if you want to buy 8 year old tyres)

P did go one further than the US specs as they measured sidewall stiffness as well as all the other stuff.

A good ish tyre shop will probably say you have to have N rated tyres (N4 now ?) and then discover that tyres that fit a boxster dont fit a 928 and then brain overload will follow.

Follow the recommendations of peeps on this list you won't go far wrong.

My personal recomendations - Toyo Proxes T1S (now replaced by T1R), Michelin PS2, Contisport (now replaced by Contisport 2.)

adam928

Ive asked around at different tire shops etc and the ones that had heard about this N-rating said it had to do with the sidewall stiffness. This mainly because of the 911s really heavy behind... Because of all the extra weight in the back Porsche mean that they do need tires that has a stiffer sidewall construction. That was what they said...