What are people's opinions on how old they let their tyres get before ditching them assuming they are using 2nd sets eg winters or doing low mileage and the tread depth is not the limiting factor. 2012 TDV8 Vogue (L322)

I’d be more concerned about condition rather than age. Any hit of cracking delamination etc then scrap them.

My expensive 2019/20 dated Pirelli P Zero's have already got surface cracks!!! Not happy.

Depends how they've been stored/used - it's UV and heat that breaks down the rubber. A set that have been stored through the summer and used during the winter will probably be fine for many years.

Michelin recommend regular inspections from 5 yrs old and replacement at 10 yrs old:

https://www.michelin.co.uk/auto/advice/cha...tyres-last

FYI, MOT rules for 8+ passenger vehicles are as follows with respect to tyre age, I suppose vehicles with fewer than 8 seats should be treated similarly:

“Tyre age
The check of tyre age applies to all vehicles with more than 8 passenger seats, other than vehicles of historical interest.

Tyre age is determined by the date code on the sidewall and will be a three or four-digit code. Tyres with a three-digit code will be more than 10 years old.

The code is usually located in a ‘window’ on the sidewall and may or may not be located at the end of the DOT number (see image below).

(example image of a date code on a tyre sidewall)

The first two digits of the code represent the week of manufacture of the tyre and the second two digits represent the year of manufacture. In the example above, the tyre was manufactured in week 35 of 2016.

Tyres over ten years old at the time of test must be failed if they are on:

any front steered axle
any rear axle of a minibus with a single wheel fitment.
Tyres not displaying a date code must also be failed. However, date codes are only required to be marked on one side of the tyre so it may not be possible to see the date code on twin wheel fitments. Under these circumstances you should advise the presenter and assume the date code is present and the tyre age is acceptable.

On tyres where the date code is illegible, for example, due to kerbing or deliberate tampering, a major or minor defect must be recorded, depending on the location of the tyre.” “If it ain’t broke, don’t fix it” -where’s the fun in that?

Some tyre brands seem to age better than others. Also as others have said the exposure to sun can accelerate aging. When I bought my M140i, I picked up a second set of genuine alloys with delivery mileage Michelin Pilot Supersports. I stored the tyres in the garage away from the window and fitted a set of winter tyres to the second set of wheels. When I needed new summer tyres I then fitted my spare set which were dated 2016 (I bought them early in 2017). The tyres are still on 3-4mm of tread but I intend to change them soon as the shoulders are starting to show signs of aging.

I wouldn’t let my tyres get older than 7-8 years. Especially on a heavy beast like a RR!
I had a blowout in my Jag XKR on the A2 whilst overtaking a lorry (quite hairy!). The car had just passed MOT but had the one old tyre on (10 yrs)
I don’t see how you can tell how much the tyre has perished due to age. That was a Pirelli tyre. It is something I am very conscious of now.