(Not the usual) Tyre Advice Please

[KPNut]

I have a 55 plate 987, with Michelin PS2s fitted. I'm very happy with them. The car has done 13k miles and the middle of the rear nearside tyre is worn down to the 'replace me' bumps[]. The offside rear is in better shape with 3 mm tread remaining. The front pair have a long way to go before I have to worry about replacement[].

All of the tyres have greater wear in the middle than at the edges, indicating over inflation. This is reflected in my other car. So my wonderful digital pressure gauge is not as accurate as I'd like. I do not do track days, but I do regularly slide the car at roundabouts, and I suspect the combination of sliding and over inflation explains the inferior condition of this particular tyre.

I am aware of Porsche reccommendations about 3mm of tread and the policy of simultaneous replacement tyres on each axel. But it goes against the grain to replace a tyre which has got 3000 miles of life left for the sake or the other wheel. Especially at £200+ a shot[]!

Thus; has anyone been brave enough to replace a single tyre at the rear? Any comment or observations to make, good or bad? I've heard the, "It can adversely affect your handling" argument, but has anyone any actual experience of this?

All contributions (including the don't be such a miser variety) gladly accepted.

Kevin.

 

[Rodney Naghar]

I did this in the summer for 2 weeks, 1 new rear, 1 old rear.
No noticeable adverse efffects, no PSM light flashing.

But then you'll be in the situation of having to repeat the cycle as the rears won't wear out at the same time anymore.....then what do you do? I'd bite the bullet and maybe keep the tyre for track days.

 

[Mark_Bennett]

If you have NOT got PSM, then I'd say go for it - in the summer....
If you are in the UK then 3mm isn't much if it's a daily driver.

If you DO have PSM then (although Rodney's experience is otherwise) you might be setting yourself up for inadvertant intervention by the PSM.

 

[Mark Elder]

We need a part-worn trading scheme. There must be someone else in the same position as Kevin. If they get together they need to buy 2 tyres between the two of them. One gets both new ones and one gets both part worn ones (and obviously pays rather less than half the cost of the 2 tyres).

Tough to make it work.

But when I have to replace all 4 of my types I'll keep the part worn front pair in case there is a trade to do with someone or in case I get a non-repair puncture just when I'm down to the same wear point.

 

[KPNut]

I do have PSM; it's standard on all 987s. Has anyone done this and then had PSM problems?

Kevin

 

[channella]

but I do regularly slide the car at roundabouts

This is a consequence of over inflation then: Under normal driving conditions only excessive acceleration would cause this, unless the surface was compromised (ice, snow, diesel etc.).

 

[KPNut]

Yes Andrew, I think you are correct, albeit exacerbated by the fact that power is only transmitted to the faster moving wheel which at a roundabout, would be the nearside. This would increase the rate of wear, particularly as the tyre is both rolling and drifting with the road surface cutting across the plane of the tread.

I am a little surprised that this thread has generated such a low response, because I suspect its a common dilemma.

Kevin

 

[Guest]

Personally I would replace the two rears and go and get your alignment checked. If the two rears are wearing unevenly yet you have the same pressure in then unless your going right all day it sounds as though you need it looking at. My rears are getting ready and its most noticeable when turning left or right out of a junction when the unloaded tyre breaks traction. If this happens at low speed I would not be too confident of the effects at high speed with having one side with plenty of grip and the other with reduced grip. Alignment wise ontact Chris Franklynn at centre Gravity on 07875850471 or look at his website on www.centergravity.co.uk . Very good guy, deals with alot of Porsches and is able to do it mobile (numbers permitting).

 

[KPNut]

Thanks Bax. I'd already decided to have the alignment done if I chose to replace both rear tyres. However, getting the tyres in South Wales is becomming quite a problem. I've yet to track down anyone who actually has PS2's available in stock, and I've tried all the usual interweb and local supploiers. In some places they are actually de-listed! This is becoming a bit of a saga.

If I can actually get two tyres, I intend to replace both and keep the part worn for emergancies. But this is turning into a large if!

Kevin.

 

[Guest]

ORIGINAL: KPNut

However, getting the tyres in South Wales is becomming quite a problem. I've yet to track down anyone who actually has PS2's available in stock, and I've tried all the usual interweb and local supploiers.

Have you tried Celtic Tyres they are wholesalers to many local suppliers and I had a full set of N-spec 18in Michelin PS for 986 within 24 hours.

 

[KPNut]

Yep! No Joy. However, I got a sniff that there was a UK delivery Thursday morning and mentioned it to a local supplier in Barry called, you guessed it, Barry Tyres. Stuart got me a pair and said they were the last of a 170 tyre UK delivery, that morning. Good price too, £212 fitted. I know you can get original Pilot Sports for less, but I think that's really good for a PS2 which appear to be in short supply.

I am not affiliated with Barry Tyres in any way, they were recommended by a colleague. I'll report back on the quality of the fitting.