calling driving nerds - sidewall stiffness

maybe a misleading thread title but nevertheless. Question to those who have considerable car setup experience and/or put a lot of emphasis on handling - which tyre is the best best you've found for the 996? (let's assume harsh coilover setup). I made the mistake of saving some £££ and went with Uniroyals. They are soft as marshmellows and ruin the handling completely. Lesson learned. I've had Goodyear Eagle F1 Assy 2 on my Cayman, but that was a few years ago, don't know how the Assy 3 are. Now I hear PS4's are not on the hard side, but somewhere in the middle - however those are rumours. Thoughts on a postcard...

I'm yet to hear anyone mention they've ever regretted buying Michelin.

Tyre feel is a very subjective thing but tyre performance is an objectively measureable thing. I tend to buy my front tyres based on Evo tyre of the year tests, which are available online. They do a good job of measuring the performance as well has describing the feedback they feel through the wheel. I buy the cheapest crap I can find to go on the back because I like the rear to be throttle adjustable.

If your looking for a stiff side wall and a high performance tyre, look at the Yokohama AD08R.

CG rate them highly, they told me I should have gone for them rather than PS2s despite the fact that I would have had to go with 275/35/18s om the rear rather than 285/30/18s. Having said that, the PS2s are N rated and better than the (N rated) Pirellis I had before.

N rated generally have stiffer sidewalls as part of the spec I don't buy n rated, but look for the higher load rated tyres to get stiffer sidewalls What was the load rating on the uni royals?

92 front, 97 rear.

I'm not sure about that Wasz. Take 225/40/18 fronts for example. Every Michelin in that size is 92Y rated, whether it's PS2, PS4 or Cup2. The N rating is just a big collaborative scam between Porsche and the tyre manufacturers. That's how after all these years nobody can actually say for sure what the difference is. It's so Porsche can charge you more for tyres while you're tied to their warranty. Going without N rating doesn't affect performance and doesn't affect insurance . Regarding the Op's question, personally I think very few of us would feel a difference during road driving between most of the high performance tyres. There's maybe a noticeable feel once you get in to track day tyres, such as Cups, R888's etc. But even then the difference is when operating at the top end of their ability. During road driving, pressures, age and tread depth will alter feel way more than the difference in sidewall. I removed 225/265 Pzero Rossos, and fitted 225/285 595RSR summer/track tyres. What's the difference during road driving. Pretty much nothing. In fact, nothing. And that's not because I have no feel. I've borrowed mates cars in the past and felt things even they haven't. I am Number 1 fanny when it comes to feel and noises from cars. Performance tyres are just that. Performing higher when needed. The only negative effect at road speeds could be the lower tread depth for clearing standing water. Right I'm off to fit Cups to the front and 20 year old Colway remoulds to the rear, as I'm a driving god. Stuff those other motorists when the rear end lets go and wipe out a line of traffic or some cyclists. That won't happen though as I catch every slide with one hand. This place is funny sometimes. :grin:

I think the combination of sidewall stiffness + the thread type on the Uniroyals is what makes them feel incredibly floaty at speeds, and makes the car literally skip over bumpy corners. Very unsettling to drive at speed. Very good in the water though

I have those Uniroyals on my S3 & they're fine; way better than the Pirelli crap it came on. I think you'll find that it's less about the sidewall & more about the ratio of tread to voids; slicks have a relatively soft sidewall & I have pictures of mine on track in corners where the tyre is displacing the sidewall by an inch or more but from inside it feels nailed to the track; it's most noticeable on the left rear in the picture below. Anything that has huge rain clearance voids is going to squirm around when significant loads are put through the bits of rubber in contact with the road. That's always the trade-off, more rubber = better feel / less squirm but poorer wet performance. The PS4 mentioned above is a good compromise with the PS4S being a step up again but unavailable in 18".

I used to run Uniroyals on my other car; they're fine on the road, and in the wet, but they are soft and the car moves around a fair bit as the tyre deflects. As such they're not great at the track, and they squeal a lot too. I found them to wear quickly and didn't replace like-for-like. At the other end of the scale, super stiff and sticky tyres are lots of fun, at least until they break away, when they just seem to let go completely, so I prefer a more progressive tyre which lets you know you're at the edge. It's a bit easier to drive up to the limit.

Out of interest does anyone know what load rating tyres front and rear are supposed to be fitted? Do they specify different between 996.1 and .2?

The answer seems to be there is no answer, obviously Porsche only recommend N-rated tyres but the same sizes can have different load ratings between brands. Tyre manufacturers recommend similarly different load rated tyres between brands but the non N-rated tyres tend to be higher load rated than the N-rated.

Way I look at tyres is A or B wet rating. Wont buy anything less. In the dry a lot have reasonable grip but its the wet where you need it most IMO. Currently got part worn Hankooks Evo2 on mine and there quite decent.