Morley says...

YOU’VE RAISED A very good point, Laurie, and I reckon it’s one that is very often overlooked. As you point out, while ever our tyres are holding air, we generally don’t give them a second thought. But you’re bang on the money with the observation that a lot of classics don’t do many miles, so tread wear isn’t always an issue, even though the tyre is past its use-by date.

We’re conditioned to judge a tyre’s worthiness by the state of the tread because that’s what’s been drummed into us over the years. But just as there are many drivers who believe that if they don’t drink-drive and don’t speed, they won’t be hurt in a car crash (‘cos that’s what the government has been telling them for 30 years) judging a tyre purely on its tread condition is a mistake.

I asked a tyre industry specialist from a major brand about this, and he told me that the general consensus right now is that sometime around the five-year mark is when you should start looking at your tyres with a view to replacing them. He reckons the five-year warranty his company applies to brand-new tyres is based on that very premise. The factors that cause a tyre to degrade include exposure to sunlight, ozone and moisture (among others) so if your car has been dry-stored in a dark place, never driven in the rain and not parked at the beach too often, its tyres could well be in better nick than a daily-driver’s tyres of the same age. Even so, my man reckons your tyres at 12 years old are really due to be replaced.

That’s why you can be confident that a brand-new tyre from a reputable distributor will still be good for the full five years even though it might have been manufactured a couple of

years earlier than the date you buy it. It will have been stored properly, and that’s what really matters.

The other thing to note is that the signs we associate with ageing – cracking and crazing – aren’t always the only factors. And some things like moisture ingress (which will eventually cause the steel belts to rust) can be totally invisible. Apparently, one of the biggest causes of tyre failure occurs when fourwheel-drive owners fit their ancient spare tyre – you know, the 15-year-old one that is bolted to the back door in rain, hail and shine – and belt down the freeway for a couple of hours. And that, apparently, is when you’ll see delamination, flung treads and a fourwheel-drive parked in the scrub at the edge of the road, waiting for a tow-truck.

And yeah, don’t forget about the spare tyre. How many times have you seen classic cars with radials on nice shiny rims and the filthy old original cross-ply spare on a steelie in the boot? Plenty, I’m tipping. Oh, and you do check your tyre pressures every month, right? And while we’re on the subject, when was the last time you replaced the engine coolant or the brake fluid? High-maintenance these motor cars.