bandit wrote:The way I understand it, it’s the sunlight that effects the rubber more than anything else, so given that most D’s spend 99% of their life in a garage the lifespan will be considerably longer
Yeah absolutely. I did say "road use", but perhaps I should have really conditioned my post with "regular use" instead. I suppose if you take the number of average miles someone does over 10yrs of regular use, and living outside, then adjust that mileage out across the number of years it takes a D' to do the same, you'll probably find that you never need to change your tyres ever again in your lifetime!
Seriously though, there will still be an ageing factor in their despite the lack of UV, but it will be a lot slower. In most cases, i'd expect that tread will be the reason most of us have to change our tyres.
I put new Rear Pirelli 600's on my car in 2015. That was the first time i'd changed them under my ownership. I bought my car in 2009 with those tyres on already. I'm fairly certain they showed a date of 2002 on them! It was the tread coming up on the MOT that forced my hand. During my time between 2009 and 2015, according to my records, i only put 8764 miles on them in 13 yrs. My new sets i fitted in 2015 currently have 2025 miles on them in 5.5yrs!