Currently on 19s Pirelli P zeros. What are the dis advantages of running on a non- N rated tyres. Thank, Cheers

 

1. More money for beer, leads to weight gain
2. Someone will hassle you its not a good idea
3. They typically last longer so you won't make friends with the tyre guy
4. Most have a little less grip on the ragged edge (where most drivers never go)

I just about put Yokohamas on mine 3 weeks ago, but they were out of stock and put PZero's back on at the same price otherwise I would be wearing non N rated right now.

 

as above. Lots of folks using Sumo III like me awesome tire, even for DE days.

 

I run Kumho....no problems.

 

I've used N-spec and non-N-spec. I've tried cheap tires like Sumitomo and expensive tires like Michelin. Personally, I enjoy the ride quality and handling of the Michelin Pilot Sport PS2 more than any other tire. I don't mind paying more for it because I find it to be that much better. As far as tire life, every brand I've tried wears out in roughly the same amount of use. Once your car is out of the factory warranty period, you can use non-N-Spec tires. I really wish that the new Michelin Pilot Super Sport was available in the proper sizes for my C4S.

You're already outside of Porsche's tested and recommended wheel/tire combinations by running a 19" wheel on a 996. Running a non-recommended tire doesn't really matter. In fact, there isn't an N-Spec option for the 996 in a 19" size.

 

Care to explain this? Where is this info available? I've been thinking about getting some 997 wheels, but they're all 19's.

 

The 996 was designed for an 18" wheel, that includes suspension, tire size, transmission, rear differential, tach, spedo, etc.... Therefore when you go to the 19"s the it's not within the original specs of the car so it will handle differently and the spedo will be off slightly, etc. Now it's only an inch in rolling so will it make a big difference? No, and loads of people do it. Unless you are seriously tracking the car, you'll more than likely never push it to it's extreme limits, especially on the street, so in essence you will not see or feel the difference.
I believe (I could be wrong here) when they introduced the 997 there was a setting in the computer to select wheel size, 18" or 19" which corrected the electronics.
So, if you like the 19" wheels by all means go for it as I said loads of people do it.

 

You can "fit" 19-inch wheels on a 996, but the car wasn't designed for them. When Porsche introduced the 997 with 19-inch wheels, they also changed the gearing by 5% to account for the larger wheel/tire diameter and they strengthened the front suspension to deal with the higher gyroscopic stabilization force produced by a 19-inch wheel/tire vs. an 18-inch wheel/tire. There isn't a Porsche recommended 19-inch tire size because Porsche never sold the 996 with a wheel that large. You'll have to take recommendations from people who have used 19-inch wheels for tire size. Heck, I've heard that you can "fit" a 20-inch wheel on a 996. That's always an option if that's what you like.

I'm not saying you shouldn't but a 19-inch wheel if that's what you like. You should simply understand the potential consequences. On the up side, they are beautiful and they look great on a 996. On the down side, they make your car slightly slower, they typically produce a harsh ride and they could lead to suspension issues in the long term. If you never plan to track your car, then it probably doesn't matter.

Paying members of www.renntech.org can search the Porsche TSB section to get a list of Porsche approved wheel and tire combinations for each model. This information is also available at your Porsche dealer.

 

Just to confirm 100% what has been posted above. Besides the 997, my ex 2003 Cayenne Turbo also had the ability, via the OBC, to choose what tire/rim combination it had installed to deal with the speedo. Suspension (air/hydraulic) was designed from day one to adapt to multiple rim sizes.

Since the question was more about tire than rim size, you can in fact use non N rated tires. It is a personal choice. Some say it is the only item between your car and a unintended object that you are about to hit, so make sure to get the best that you can, but the best is a term that has different meanings to different people.

I currently have Michelin Pilot Sport on my C4S, and I have to admit, that they ride as loud and as harsh as my old Falken Azenis RT-615 I used to have on my old C2 (that tire was a barely street legal tire, more in line for auto crossing). When time comes to replace these, not 100% sure I will go for the N spec tires.

 

Thanks for the reply guys! I am not planning to track the car with the 19's. I still have my 18's so Ill just swap it when the time comes to track it.
Let me just try to summarise it, N rated tyres doesnt really make a difference not unless you reached the ragged edge and I don't plan to go there anyways, but the increase in the rolling diameter of the 19's make a lot of difference? Anyone out there with experience with the 19s?

 

You may get a little rougher ride but more than likely you won't notice the difference. If you like the look go for it.

 

N-spec tires have been tested and approved by Porsche to meet Porsche's minimum performance requirements. Porsche manufactures cars that can truly be driven to work every day during the week and then driven on the track on the weekend without any modifications. A car with N-spec tires lives up to Porsche's requirements for performance.

There are many tires made by the same manufacturers in the same sizes as N-spec tires. You can get a Pirelli P-Zero that is not N-spec in the same sizes as the N-spec version. Is there a difference? I don't know. That's a well-guarded secret. I've heard all kinds of theories, including stiffer side walls in N-Spec tires to deal with the weight of the engine over the rear wheels. I have no idea if this is true or not.

So, back to the N-spec requirement. Are there non-N-spec tires that meet Porsche's minimum requirements? I'd say there probably are. There may even be some that exceed Porsche's requirements. The fact is, Porsche hasn't tested them and so we don't know. If your car was still under the manufacturer's warranty and you ran a non-N-spec tire and had a problem, then you may have trouble. The use of a non-recommended tire may void your warranty. If your car is no longer covered by the factory warranty (I don't think there's a 996 in existance that is still covered, with the possible exception being some mid-2000s models that had CPO coverage), then it doesn't really matter. If you find a non-N-spec tire that you like, then run with it!