OT: tires

[Chris J Dixon]

Mine gave a warning after a period of wheelslip getting my caravan off a muddy site, but reset itself after a couple of miles on tarmac.

Chris

[alan_m]

If they fitted new senors you will have seen it on your bill.

However they may have swapped two sensors between wheels and the car may not be seeing the same sensor on the same wheel. You may have to go through the routine of selecting the calibration routine and then perhaps going around each tyre in turn and letting out air until the computer detects which sensor is fitted at each corner of the car.

BUT before you do that just see if there is a simple tyre pressure reset function in the cars computer menu.

What he did

One of the joys of using Kwik Fit

[Brian Gaff]

Surely the pressure should not be that critical as when running the tyre and the air inside it warm up anyway. What the actual warnings do is really debatable. They should really monitor it over time and look for a trend to see if there is a slow leak I do not think that the issues you experienced with the sensor are connected with a sudden flat. I do not drive of course but have been in many a car which has suddenly had a tyre go down both with a whimper or a bang and the cause is normally an object run over or some unfortunate abuse due to a curb. Brian

[Brian Gaff]

This lark of having no spare or a crap spare in my view is false economy. Brian

[Martin Brown]

You can get away with a range of pressures but too much or too little compared to the load in the car affects the grip and the wear pattern. Too much and you scalp the middle of the tread, too little and you destroy the edges. Bad tracking can seriously shorten tire life by rapid wearing of the inside edges of the tyres which is worth watching out for. (and hard to see without getting under the vehicle)

The other common cause is a failure to even look at the your tyres before getting into the vehicle. I have lost count of the number of cars I have seen driving down the high street with one wheel flat.

I have seen false positives on these "smart" wheel pressure check things. A friends car was showing "tire pressure fault" when they arrived here but a check with my pump showed they were all OK.

Unfortunately since they didn't have the car manual in the car I couldn't easily reset it for them. The apparent fault condition seemed to have been a direct result of a recent main dealer servicing :(

I find the latest generation of smart sensors a bit annoying. I have a parking light sensor sensor failure (ie the parking light is actually working but the sensor to test if the parking light is working is not). The main dealer refuses to disarm the alert and would charge an arm and a leg to replace an otherwise fully working sealed beam unit.

[dennis]

Some systems are clever enough to work it out for themselves. Not the ones that use the anti lock sensors AFAIK.

You can move the wheels about on the wife's astra and it will work out where they are.

[Martin Brown]

There is a problem though with modern vehicles in that the wide tyres have a spin handedness so you would need to carry a spare for each side of the vehicle. A small spare good for 50mph is a fair compromise. Run flats have the distinct advantage that a blowout at speed is pretty much a non-event and you don't need a spare at all = more luggage space. The disadvantage is their ludicrously high price.

[mm0fmf]

Had this on a hire car in Fuerteventura last year. I hit some lava debris on a minor road and there was a bang and lots of messages about checking tyres lit. Bloody big tear in the tread and sidewall. I eventually found there was a spare, Vauxhall Zafira had a full sized tyre tray underneath that you could wind down from the luggage area. But it had a space saver in it and you couldn't really see the tyre from underneath. I rang the hire company who did confirm there was tyre but it may be hidden! When swapped it was ridiculously small compared to what came off and quite under-inflated. Should have been at 60psi but was well below that. Luckily I only had to drive 15kms to the airport at about 40km/h, there were even more warnings about tyre pressures all the time. Hire company just gave a me a new car and half a tank of fuel for my inconvenience of having to swap the tyre.

[T i m]

(that last one is a good tip).

Much better than the vast majority I reckon. ;-)

Cheers, T i m

[mm0fmf]

My current car has TPMS sensors in each wheel reporting the pressure in Bar. Pressures are typically 2.3 at the front and 2.5 at rear a few hundred yards after starting off from cold. Within 5 miles of gentle driving that will be 2.5 / 2.7 on Y rated tyres.

I've had ABS based pressure monitoring which worked but could take a while to start warning about pressure issues. Now have wheel sensor based which can respond quicker. But cost what £35/45 per wheel every 5 years or so.

[mm0fmf]

Maybe they knew it was beyond you?

[Dave Plowman (News)]

On the last car, which had near new tyres when I bought it, two were ruined by woodscrews. Both too close to the edge to be repaired. And about a couple of months apart. It also picked up quite a few parking dings. I think it was cursed. The same make replacement has done very much better.

[alan_m]

Spare tyres are unlikely to have sensors so there will always be a warning if you fit one. My car's handbook warns of this situation. In addition, when fitting a wheel with a new sensor you may/will have to perform a calibration to identify all 4 sensors and their position on the car. This is not something you want to do at the side of the busy road.

[T i m]

<snip>

So?

Did you know such things have an index ... and you really should have at least familiarised yourself with all the features on your vehicle before you set off (it says in the front). ;-)

Cheers, T i m

[Dave Plowman (News)]

No real point in carrying a wheelbrace and jack in my car as it doesn't have a spare. ;-)

[Dave Plowman (News)]

Just changed mine. According to the dealer, service records and date stamp they were the originals. And did 32,000. Only one was actually illegal. Just as well at near 1K a set. ;-)

[Dave Plowman (News)]

Ever watched then torque up a wheel fixing? Did they go and check for the correct figure first?

[Dave Plowman (News)]

You fit tyres of a size etc not approved by the car maker?

Why would they look up a chart when the tyre pressures are inside the driver's door on every car I've had for many years?

[Dave Plowman (News)]

My car has different tyre sizes front and back. ;-)

[Dave Plowman (News)]

If you're going to start a new tread on an existing subject, you could correct the spelling. ;-)