Cars are for the most part now so reliable that it’s only those of us who were around in the 1970s or even further back who have clear memories of passing quite large numbers of vehicles stranded on the hard shoulder during the average journey. What their drivers were often doing was getting the spare wheel out of the boot.
By contrast, the spare tyre most people our age worry about most often is the one round our midriff. Indeed, many new cars do not even come equipped with a spare tyre, but instead provide the driver with a can of sealant. The improvements in technology which mean that it is possible to drive for a fair distance even on a damaged tyre are, however, a bit of a mixed blessing.
The RAC estimated that it was called out about 62,000 times a year by company car drivers without a spare wheel – making fleet drivers six times more likely to be stuck without a spare. The necessity of taking the vehicle to the nearest tyre fitting centre – which might, of course, be some miles away – rather than simply fitting a spare by the roadside obviously imposes a high cost, in both time and money, on the motorist and motoring organisation alike. And if it happens late at night or on a day when the fitting centres are closed, you’re stymied.
But nowadays, it isn’t just drivers without a spare who have to call on the RAC, AA or other motoring organisations. Because the nuts on tyres are often put on with pneumatic torque guns, those of us who imagine that we are perfectly capable of changing a tyre, and carry a spare in the boot, may find that we can’t unfasten the nuts – even if you happen to have an extendable torque wrench. Another impediment is that the jacks supplied with modern cars (assuming one is supplied at all) often seem to be flimsy, and don’t inspire much confidence.
Other advances in car technology mean that the average driver can’t now do much about what’s under the bonnet, even if they know something about engines. And for the most part, that inconvenience is offset by the fact that cars are so much more reliable than they were thirty years ago. But the inability to change a tyre is surely one instance where things are worse than they used to be.
Pre-puncture sealants (which are designed to seal any leak as soon as it occurs) may enable drivers to continue their journeys, but they also mean that the driver may have no idea that the tyre is damaged – which obviously increases the risk of more dangerous, potentially catastrophic, failure later on. Sealants used after a puncture has occurred should never be regarded as anything but a temporary solution.
It is often suggested that the use of sealant, rather than providing a spare, has become more common because of EU pressure on manufacturers to reduce emissions – and reducing the overall weight of the car is one means by which they attempt to meet their targets. If so, it’s a short-sighted advantage from an environmental point of view, since one of the problems with tyres which have been repaired by sealants is that it is usually impossible to repair or recycle them. The ability of modern tyres to keep going after they’ve been damaged may be one of those improvements which actually makes matters worse.