Replace 5 year old tyres?

[autojack]

When I moved here and shipped my 911 over, the rear tyres were worn out and had to be replaced to pass roadworthy. I had the shop go ahead and replace those two, without thinking about how old any of the tyres were. I later checked and realized the fronts were already ~7 years old, so even though they had plenty of tread left, I probably should have gotten 4x new ones [shop could have made some money, they should have checked]. Fast forward to today, five years later. The car didn't get driven too much for various reasons, including 18 months of storage while I built a garage. Now I'm going to be driving it at least once a week for fun, and I soon remembered about the old front tyres. Checked them again to refresh my memory and, yow, they are 12 years old! Obviously replacing them straight away. But the rears... 5 years old and hardly used. Should I save a few hundred now and drive them for another year or two? Or replace all four? The rears are Pilot Sport 3's, fronts are Pilot Exaltos, so I'm planning to get 2x Pilot Sport 3s or 4s for the front.

[Joz]

Out of curiosity, have they developed any hardening/ flat spots where they’ve rested?

[autojack]

Just now, Joz said:

Out of curiosity, have they developed any hardening/ flat spots where they’ve rested?

Definitely no flat spots that I can feel, I've put a couple of hundred kms on them since taking it out of storage and they seem to run smooth. But the steering feels SO heavy, worse than I remember, and I put that down to the 12 year old front tyres. I fully expect to see a huge difference just from replacing the fronts.

[Peter M]

I would expect the steering to become marginally lighter as the tyre ages.  I assume the pressures are correct?

Also consider Bridgestone RE003's.  Excellent street tyres and surprisingly inexpensive particularly when purchased on their frequent 4 for the price of 3 sales.

[autojack]

2 minutes ago, Peter M said:

I would expect the steering to become marginally lighter as the tyre ages.  I assume the pressures are correct?

Also consider Bridgestone RE003's.  Excellent street tyres and surprisingly inexpensive particularly when purchased on their frequent 4 for the price of 3 sales.

Excellent question on the pressures, I think they are correct but TBH can't remember if I've checked them since taking it out of storage. 

I would consider a brand change if I was replacing all four, but it seems like if I'm just replacing two it might be better to stick with Michelins. That said, tyres are an area of lesser knowledge for me.

[P-Kay]

Sounds like you've forgotten the weight of the steering on these old things  

I agree with Pete, check the pressures and you simply get use to it.

I'm getting PS3s fitted tomorrow, but I have also used and also recommend RE003's. Either way, you can't go wrong on fresh rubber

[LeeM]

5 years? They'll be right mate 👍

[reedminor]

Drive the wheels off the car , wear the back tyres out.

[AndrewM]

Depends what you want or expect. The tyres are likely to be hard, and have less grip than they had originally. The will also likely not great in the rain.
As you only seem to drive occasionally, it would probably take another 5 years to wear them down, so you would have substandard grip until then.

Personally, I would replace all 4.

[sus911]

Unless you're planning on using the car for bank robberies I wouldn't worry. Different story if we're talking 2 wheels!

[Joz]

Ok is there a set period in which otherwise good looking tyres time out?

[Peter M]

Joz, 

No legally enforceable age limit but recommendations vary from 5 to 10 years.

Like all things I think it depends on a number of factors.  The tyres on my box trailer for example get replaced when the rubber is significantly cracked which could be every 20 years depending on how diligent I've been in protecting them from direct sunlight

In my experience with torsion bar 911's the quality of the tyres play a huge part in how enjoyable these cars are to drive in the twisties.  I've found crappy tyres, irrespective of being brand new or aged, exaggerate their undesirable traits of understeer and oversteer while good tyres make them quite benign.  For the same reason, I would be thinking of replacement every 6 to 10 years.

In autojack's case I'd check the pressures, check for damage or cracking, drive the car and see how they feel.  If they don't feel confidence inspiring, I wouldn't over think it and just replace with a set of RE003's when next on sale.  Times too short to put up with crappy tyres on these cars.

[autojack]

I did check the pressures and they were definitely low, so I raised them to 28 front, 34 rear. Haven't been for a drive yet since then, so we'll see how it feels. I'm going to replace the fronts and see how I go. Most of my driving is cruising, not even a lot of twisty hard roads, so I suspect these rears will be fine for another year or two of my use.