Recently witnessing a nasty accident on the motorway in Gran Canaria, where fortunately all the passengers survived unscathed, led me to ask some questions about the cause. Apparently, one tyre had exploded, which was due to the age of the tyre and failure of the rubber. For me, this was an unknown phenomenon. Although I am careful about regularly checking the depth of tyre tread from time to time, and changing a tyre when necessary, I frankly had no idea that tyres ‘age’ and that rubber deteriorates. Judging from conversations with other expats, most did not know this either.
We have a second vehicle, which is not heavily used and, since we live on an island, has very low mileage, because there are few long distances that can be travelled. The vehicle is parked on the road outside our home, and I have to admit that, for much of the day, it is parked in the full glare of the sun. The tyres all look as good as new, but I took the car to the tyre depot for a check - just in case.
Jorge, the mechanic, looked horrified when he pointed out that the tyres were made in 2005, as a coding that represents the date is clearly inscribed on the tyres. With, not undisguised delight, Jorge went on to point out some deterioration of the rubber, as well as unevenness on the walls of the tyres. He made that inward sucking of breath that people make when they are about to impart bad news. I prepared myself. They were not exactly bulges, Jorge explained, but they were heading that way. Jorge then went on to show me a tyre that had exploded, and inferred that the same would happen to me unless I bought a new set of tyres. The exploded tyre was not a pleasant sight, but it did help me to understand the problem.
Apparently, the performance of tyres deteriorates with age, because they contain anti-oxidising chemicals to slow the rate of ageing, but they need to be in use to be effective. My low mileage vehicle was deteriorating on the roadside, and because of the intensity of the sun and heat, the ageing process was accelerated, making the tyres unroadworthy. Low mileage, older cars tend to be at most risk from premature ageing, explained Jorge, continuing with a sharp intake of breath and shaking his head.
Of course, the age of a tyre and when it should be replaced depends upon many factors, but Jorge reckons that 6 years is about the age limit in a hot country. Living on an island, we also have a particular problem in that tyres rarely reach the end of their life based upon the depth of tread alone. Distances tend to be short and expats, retired or otherwise, do not travel very far in a year.
Jorge pointed out that the date that tyres are made is clearly inscribed on the wall of the tyre, in the form of four numbers. These numbers indicate the year and week number that it was made; for example 2612 will be week 26 of 2012. This information can also be used to ensure that you are buying tyres with the longest shelf life possible.
Jorge had successfully made his point and I reluctantly agreed to buy four new tyres. I handed over my credit card, but I am now pleased that I did so since tyres are the only contact that there is between the driver and the perils of the motorway. I think it was a good investment.