Tyre tread patterns

[daviemck2006]

My c4 vts had a 15" space saver when I got it, not only not the correct spare it had FORD stamped on it. It would not even go on due to the centre bore being smaller than Citroen. I was lucky and got a 17" resolfen, which were the wheels on the car from a scrappy on e-bay for £42 if I remember correctly. In fact theres another avenue for qprdude to explore. Look for a 19" alloy with a decent tyre then put the worn tyre in the boot. Ok it's a worn spare, but if it's ok right now it will still be ok as a spare for quite a few years, then if he has a flat, at least all wheels are the same.

[SwissSPEC]

I rotate my tyres between summer & winter, so they get a nice even spread of wear, so i don't tend to suffer with too much difference between the wear on the front versus the rears I'll personally stick to understeer than oversteer as its much easier to sort out & doesn't give you as much of heart attack when it happens. Speed isn't necesserily the issue when the tyres lose grip, there is a roundabout near to me which in certain conditions is very greasey, it looks fine & can even appear almost dry, but can be lethal even going at quite moderate speeds. It was quite amusing following a load of cars who were turning off said roundabout going the same way as me & i noticed everyone one of them sliding all over the place with some cars gettng more out of shape than others & the usual brake lights coming on. I thought nothing more of it & kept my usual speed up & low & behold the front went mega light & the car started understeering, a gentle lift of the throttle was all that was required to bring the car back in line, but i was amazed at how little grip there was, i was doing less than 25mph.

Winter tyres on the front with summer ones on the rear just spells disaster in the snow

The issue i have with putting tyres on the front with more grip than the rear, is in certain conditions the car has the potential to still turn around & spin, you'd have to be on the smoothest road in the world & with your steering dead straight, all your suspension with the same amount of wear, all your tyres with the exact same wear etc..& do the smoothest emergency braking for the car to not go slightly sideways as a minimum. If you know of any roads like this, can you please contact Sheffield City council, they've got a lot to answer for

Tyres always gets a healthy debate going, all we need to add now is politics, religion & sex into the mix & it could become chaos, haha...

[qprdude]

I once knew a vicar who put new tyres on the front of his car and then crashed into the back of a local politician who was having "censored" in the back of his car.

[Jodyone]

The issue i have with putting tyres on the front with more grip than the rear, is in certain conditions the car has the potential to still turn around & spin, you'd have to be on the smoothest road in the world & with your steering dead straight, all your suspension with the same amount of wear, all your tyres with the exact same wear etc..& do the smoothest emergency braking for the car to not go slightly sideways as a minimum.

I take your point here, in theory at least. But do worn tyres- shallower tread sipes- actually offer lower grip, in average situations? Presumably the rubber compound, surely an important determinant of grip, is the same all the way through? I understand that tyres so worn they're falling apart might start to grip unpredictably at their limit, but I'm surprised if that degradation in grip is a smooth curve that correlates to tread depth. Potentially, when fully slick, they might get momentarily better in dry conditions (before they fall to bits!)

Also -considering your point- even if you're right, the difference between new and worn tyres can't be so extreme as to throw a straight-line-braking car into a spin that it wouldn't be heading for otherwise, can it? A hard-cornering car, maybe. But nobody does that, normally.

In which case, we're back to my point (well, Mike's). Deep water sipes are very useful against a growing front of water, which only practically happens to the front tyres. Additionally, casing damage is not unknown and some tyres develop bulges and structural failures over time that easily go undetected, but may fail in use. I'd rather a surprise blowout on a back wheel than a front.

[SwissSPEC]

Worn tyres offer less grip than tyres that have more tread, the rubber doesn't overheat when there is more of it.

What i was trying to say regarding tyre wear is that if you were able to accurately measure all 4 tyres, they would all be slightly different to each other & that the wear over each tyre would also vary as well depending upon tracking, driving style, you may take corners where you're turning one way rather than the other at slightly different speeds without actually noticing that you favour one over the other, & combined with uneven roads etc.. its just not possible to have tyre wear that is uniform because of so many factors, hence why even in a straight line, there is the potential for a number of your tyres to have different grip levels which can cause the car to brake at a slight angle, add in slightly uneven weight distribution of most cars as well, and you can see there is the potential for an ABS/ASR/ASC equipped car to still not come to a complete stop in a straight line. Add in wet weather & these characteristics are exacerbated as grip levels can plummet, i'm of course talking at the more extreme end of stuff, rather than pottering along doing 30mph, which in dry weather you wouldn't probably notice a massive difference if you had 4 different chinese ditch finders with uneven wear. Its when you're going much faster & suddenly need to swerve to avoid something or brake suddenly whilst also having to steer away from potential danger, bad enough in dry weather, but in the wet, hmmm. This is why i prefer 4 matching tyres which get rotated every 6mths, so if that awful situation arises, i've got a better chance of either avoiding it, or i'll hit whatever at much less speed.

Erm, a blow out on a front tyre is far safer than a rear one, the car will go into a viloent spin when a back tyre goes, not an issue in a hydraulic citroen of course

This is an interesting video: " onclick="window.open(this.href);return false;

[Jodyone]

@SwissPEC: Thank you, I did gather your point about straight-line braking but I'm still unconvinced about that. However, I stand corrected on tyre wear and blowouts, I think!

[Northern_Mike]

I'm sorry but that's partly nonsense. I've had front and rear blow outs at speed in various cars and bikes. I've never had a car, hydropneumatic or otherwise go into a violent spin! The only time I crashed due to a puncture was in Xantia, when I was going round a left hand bend and the right rear tyre ( a newish Michelin ) suddenly deflated.

Sent from my GT-I9300 using Tapatalk

[Stickyfinger]

This is an interesting video: " onclick="window.open(this.href);return false;

Well I'm glad Tiff agrees with me, anything with "Grip" is better as you stop better in wet and other demanding conditions.

I thus put them on the hardest working axle if that is a choice I have to make (I try to avoid that choice if at all possible)...edit, I rotate at front half life then get 4 new ( I think I will sell the two spare 4mm tyres to some of you guys )

[daviemck2006]

Ok so you put 4 new tyres, all the same on your front wheel drive car at the same time. As soon as you start driving it the fronts wear quicker than the rears. after, sat 10000 miles fronts may be 1/2 worn and rears 1/8 worn. So you have poorer tyres on the front than on the rear. At 20000 miles the fronts are done and rears 1/4 worn. Put new on the front. After 30000 miles fronts 1/2 worn rears 3/8 worn, poorer tyres on front. After 40000 miles front done again, rears 1/2 worn but starting to perish so I would dump them with 1/2 tread remaining. Goes against the grain for me completely. I'm counting a tyre worn and needing replacing when it gets to 3mm, so I will be dumping tyres at 5.5mm tread remaining. I would always put my new tyres on the rear and move the rears forward. When the rears go forward they still would have 7mm tread remaining compared to the 8 mm new ones, and I would get the full value out of each tyre. But then I rarely keep any car long enough to wear out tyres. On a different drive layout, namely my freelander, it has to have the tyres with most tread on the rear or else it will chew the differentials to pieces, and my one has 2 pairs of tyres, nearly new on the rear and about 1/2 worn on the front, so if I have it long enough to need tyres, I will have to put the new o the rear and move the rears forward. Incidentally both pairs are budgets that I have never heard of and the thing sticks to the road like glue. That must show the benefit of the 4 x 4, even though it is like 80% front drive until it senses slipping when it progressively adds more rear drive (I think lol)

[SwissSPEC]

I think you've mis-undestood, what i've said regarding tyre rotation, i have a winter set of tyres & a summer set of tyres, they get approx 6mths usage each year & every year i rotate both sets of tyres from the front to the rear, so i tend to do about 12k a year, so every 6k i change to the other set of tyres & when i then go back to say my summer tyres, i rotate those around from when i last used them. My vredestein (summer tyres) are still legal & are about 7 years old, so they have effectively been getting 3.5 years worth of wear which equates to 42k worth of miles driven. Apologies if that doesn't make sense or if i misunderstood your post daviemck2006?

Northernmike, only partly nonsense, thats one step up from nonsense then All tyre blowouts can be safely controlled if you know what you're doing, its those unfortunates who have limited driver skills that come a cropper. I've seen some videos on youtube which illustrate a front wheel blow out has less of an effect on a car, yes it will try to steer one way when that tyre goes flat, a rear tyre blowout causes an oscilation which if not controlled can then cause the back of the car to start weaving from side to side & if you do the wrong thing, oops a massive high speed spin.

[daviemck2006]

The winters and summers getting rotated makes sense to me. In fact just away to take off my daughters winter 17 ' s on her astra and put on her summer 18's which have 2 tyres that have done 20 k on the back and look like new and need 2 new which will go on the back. The ones which come off have done 20k on the back and 20k on the front and down to 2.5mm.
My post was if, say on said astra, if she only ever put her new tyres on the front, she would be dumping her rears at 4 to 5mm with the side walls perished and wasting tread, whereas how she has done it up till now she's got the good of all tyres. This is the first time she has had winters with different wheels so things will be different, and probably when winters go back on the best 2 will go on the front. I'm not too good at explaining what I mean sometimes lol

[SwissSPEC]

No worries about explanations, this is the only problem with typing away of forums, sometimes something can have more than one meaning, or just not make any sense

Talking of tyres, i've just ordered some of those Dunlop Sport Blueresponse 205/65/15's for the C5, fingers crossed they'll be as good as all the tests appear to indicate

[Northern_Mike]

This is an interesting video: " onclick="window.open(this.href);return false;

Well I'm glad Tiff agrees with me,

He agrees with me too. Here he is, about 50 seconds in, getting some predictable oversteer in an FWD car, which might surprise SwissSPEC.

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I had a Puma or two, they're hilarious

[Stickyfinger]

This is an interesting video: " onclick="window.open(this.href);return false;

Well I'm glad Tiff agrees with me,

He agrees with me too. Here he is, about 50 seconds in, getting some predictable oversteer in an FWD car, which might surprise SwissSPEC.

" onclick="window.open(this.href);return false;

I had a Puma or two, they're hilarious

Its not that you cannot get under-steer, its that it is not easy to control it on any surface other than a constant one.
The "snap-back" generated by even the smallest increase in grip or regaining grip as the speed drops catches out all but the most experienced driver. Tiff shows this only to well as his work rate is massive.

[vborovic]

Maybe not a direct relation to the problem, but I just wanted to share that on Monday I'm gonna get 4 new Uniroyal RainSport3 tyres for my car, 225/55/17 ... They should be the best of the bunch on paper, and I've got the set for a fair price (and the DOT is 1014) ... will let you know how they drive after I've covered 500 km (the average customer reported threshold for them to start gripping as intended is 200 km) ...