Last time that I had some new tyres fitted, at Kwik Fit as it happens, who served me very well, they told me that they would be doing a free steering geometry check. As I sat waiting for the car, I began to feel a touch uncomfortable though. The attitude of the staff member who had told me this (I think he was probably the branch manager) was beyond criticism, but I still felt rather vulnerable to possibly being told that my steering was out of alignment and that I would need to spend, shall we say, £40 to £50 to have it corrected. I was pretty sure that I had no such problems, as I keep a close eye on my tyres for uneven wear, and I had never, to my recollection, ìkerbedî either of the front wheels. Well, as it happened my concerns came to nothing, as I was told that my tracking was fine, but I still feel that (with apologies for any sexist inferences) a lady might easily get taken advantage of in such circumstances. I wondered if you had any thoughts on the subject, on whether cars do often have faulty tracking, and whether they do get correctly and accurately re-tracked when they are found to be (supposedly) incorrect?
I think that I would share your concerns Harry. We need to briefly consider the matter of steering geometry, and why it is different in some cars from others, in terms of the ìtoe-inî or ìtoe-outî angles specified by manufacturers. It’s not just to minimise tyre wear, for instance, and the ìcorrectî geometry settings are not necessarily even the optimum for minimising tyre wear. The geometry settings are related to steering and handling characteristics, and are sometimes specified to increase steering feedback, or increase self-centering, and even to promote understeer. Some of such characteristics are arguably simply a matter of personal preference, rather than ìcorrectî or ìincorrectî, and it would not be ìwrongî in absolute terms (although insurance companies might argue otherwise) to use settings that were (within sensible limits) what you found likeable, rather than manufacturer specified. But bad driving can severely disturb geometry settings, often due to causing actual damage to steering components by bending them, and that’s when significant tyre wear and dangerous steering characteristics often can appear. Sometimes the steering wheel may even develop an ìoff-centreî position when driving straight ahead, and that’s something that calls for immediate action, as it can lead to rapid wear, damage to the tyres, and unsafe handling.
So good drivers will keep an eye on their tyres and hopefully spot any uneven wear, although any symmetrical uneven tread wear (such as both outside or inside shoulders apparently wearing excessively, or even both shoulders on both sides) can simply be the result of incorrect tyre pressures, or even related to the loads carried, and perhaps the way that people drive around corners on their regular routes. It’s surprising though how many enthusiastic drivers have little or no understanding of the mechanics of cars, and I’m still absolutely gobsmacked when I read of people (of either gender!) continuing to drive in the face of alarming dashboard warning lights that indicate serious problems ñ like low oil level, diesel particulate issues, extremely low adBlue fluid levels or faulty tyre pressures, and so on. I can actually relate one recent personal experience, when some friends proposed taking me for a ride in their new car, which they had, by then, owned for several months. Both are heavy people, and they mentioned they had a problem with a tyre pressure warning light, which they had apparently managed to cancel out, but which then reappeared. It made me decide to check their tyre pressures, and I found, to my utter amazement, that no single tyre was at any significantly different pressure from any other, but that they were all set at just 20psi all round, as they had obviously been ever since the car had been delivered to them new! They had, unsurprisingly, thought that their car was steering somewhat less responsively, and riding somewhat more softly, than its fairly similar predecessor, on similar sized wheels and tyres. Amazing, and no tribute to the supplying garage!