Years ago when cruising speeds were low and roads comparatively deserted, worn or faulty tyres did not much matter. This writer often drove his Austin Sevens on bald covers, and a Gwynne 8 whose tubes were visible through the holes in its rubber. Even the police, more concerned with the newly compulsory third-party insurance, did not care.
The coming of motorways changed all that. Free from speed-limits, the M1 soon became a killer of tyres as well as engines, and it became necessary to introduce legal requirements applicable to tyre-condition and tread depth.
Now, in 1988, following a Gallup Poll of 6728 cars at eight motorway service stations across Britain, National Tyres estimates that about 170,000 motorists are aware that they are running on a full set of illegal tyres. Of the cars checked, some 13% had one or more unsafe covers.
Modern tyres hold correct pressures for long periods, so daily checks might seem unduly drastic. But it is distinctly disturbing that this poll suggests that 19% of drivers never check tyres for condition or pressure.
Tread depth is not the only factor, but is important in obviating bursts which in vintage days were exciting but at today’s speeds can be fatal. Yet the United Kingdom is satisfied with a legal minimum of one millimetre, over 75% of the tyre’s width. No other country allows such tolerance, except Spain, where having “a visible tread pattern” is sufficient; elsewhere a 1mm minimum applies over the entire surface, with the USA demanding 1.5mm, Switzerland 1.6mm and Austria 1.6-2.0mm (depending on weight).
The large quantities of tyres supplied for new cars being subject to hard bargaining between tyre and car manufacturers, the trade makes most of its profit from replacement rubber, to it has a vested interest in EEC plans to make 1.6mm of tread over 100% of the surface the legal minimum. Yet with cars becoming ever faster and 80 mph motorway cruising perhaps in sight, tyre-safety is only common sense.
What it does not cover is space-savers. No test case has yet established whether these are legal. Apart from which, where do you stote a punctured full-size dirty wheel?
The new Fiat Tipo, loudly acclaimed as a top contender in the world’s sales-race, has been criticised for not having a turbo petrol option. But surely, unless public opinion about these little wheels has changed drastically, the Tipo’s space-saver equipment (unusual for a car of its type) could be a bigger sales-loser? Will the space-saver be its Achilles Heel?