Tyre age.
 

I have a Bridgestone space saver tyre which has never seen the road since it was supplied with the car, back in 2006. It has no cracks, glazing or splits anywhere (including between the treads), in fact, if it wasn't for the date stamp I would have said it was a brand new wheel and tyre.
I do not intend replacing it, but thought I would canvas opinion among the other forum members.

Assuming it's kept in the boot, away from road debris, salt and more importantly, harsh UV light from the sun, then it should look brand new. The one in my 02 insight was the same.

Replace it.
Spare tires have about a 10 year service life, and just being inflated puts them into service.
Looking brand new on the outside doesn't tell what the inside looks like, nor the microscopic condition of the materials.
Many have put an old spare, that looked new, on, only to have it come apart once they got on the road.

If it were me I would replace it every 7-8 years or so just to be safe and more certain in case of need.

I vote for replace, ya might find a newer one at a salvage yard for cheap
(or get a can of fix-a-flat & hope for the best) !

Wonder what percentage of new cars still have spares? My past 4 or 5 cars have had the old can and compressor alternative. To be fair, the extra space in the boot, and weight/fuel saved has been more useful and cost saving in my 14 year driving career, especially considering I've never had a puncture... yet.

I contacted Bridgestone direct, and here is a copy of the email I received:

Thanks for your mail, which has been passed to me for reply.

For this space saver tyre, if the tyre has been stored in good condition and is displaying no signs of ageing then it should still be suitable for emergency use. However I would stress that space saver tyres are a temporary mobility solution and if used, should be changed for a full sized tyre as soon as possible, driving for a maximum of 50 miles at 50mph.

As with any natural product, rubber does age and will become more susceptible to cracking as it does. The rate of ageing depends on how the tyre is stored and what it is exposed to. We cannot offer an official cut-off point at which a tyre should not be put into service but based on my own knowledge I would recommend changing a tyre of this type once it is 10 years from date of manufacture.

I hope this helps, and if you need any more info, let me know.

Best regards
Pete

Peter Moulding
Lead Field Engineer
Bridgestone UK Ltd

I believe that UV light is the most damaging to tires, I always store my winter / summer tires under a blanket in a heated garage during the off season. When I had my Honda, I used a 13 year old space saver tyre that was never used and looked brand new; didn't have any issues driving it 250 miles before replacing the original tire.

If I had a choice I would rather have a fix-a-flat spray in the boot than all that extra weight. My Mercedes has a low profile spare (to miss the big brake discs), a compressor, special lug nuts, the jack and some gloves; probably weighs about 60lbs in total. I only had one flat in 18 years.

Oxygen is another agent that ages the tire, and there is little that most people can do to keep it away from the rubber.

Another vote for replacing it to be safest. Rubber ages and degrades. That's normal. UV rays and weather accelerate that degradation, but lack of those factors don't negate degradation.

Tire rubber is like a motorcycle helmet's interior padding: it degrades over time, and even though it's expensive to replace, you want to make sure it's performing at 100% when you need it. If you never need it, then throw it away; don't keep it or replace it ;-)