I was wondering what the forum consensus on this was.
I have had to have one front tyre replaced today because of a slice in the inner side wall. The front have got down to 3mm tread depth after 24,500 miles (not bad!) and would last a fair bit longer.
So now it will have one wheel with 3mm tread depth and the other with 8mm. The tyres are 225/40R18's so the circumference difference will be about 30mm. Or over 1km the new tyre should resolve 500 times and the old one 508 times but it won't if it's on the same axle?!?!
If it was my choice (and I'm arguing my case against pointless bureaucracy) it would be to get the other changed at the same time. But you cam imagine it's proving difficult to get anyone on the phone to agree to this because it's a company car.
So guess how much the pro-rata early swap of the tyre would be charged at.... £25. So we're costing more talking about it. And whilst they argue about it I got a hire car ;-)
More worrying I suppose is the car had a screw in a rear tyre the other week and this slash was either not there or visible when they had it on the ramps and checked the other 3 tyres. Except it's apparently pretty bad and through to the cords. No loss in pressure but either it happened in the last week or it was missed the other week.
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Doubt you'll notice any difference on the road.
I'd have changed both if it was my car as I usually change at around 3mm anyway.
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I've noticed at approaching 3mm they are not clearing water as well as they before - obviously you'd say.
But having one at 3mm and the other 8mm seems to big a difference. The rolling circumference difference is about 30mm.
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It's a company car. Just turn the radio to your favourite station and forget about it. You say you've only done 24,000 since you've had it, so it's not like you go very far in it is it ?
😉
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But I do some longer journeys and then lots of shorter ones therefore safety (mine and others) is important. The ability to dispel water from 8mm of tread vs 3mm will be a big difference.
Turning the radio on does not make it safer.
So on the motorway, standing water will be dealt with differently by a wide margin by one vs the other. If it was a few mm difference I'd say nothing. 5mm is a difference of 30mm on the rolling circumference.
Ironically it's cost the company over ten times the cost of the early replacement tyre so far. They only want £25. I said I'd pay but it still needs to be authorised and a purchase order number.
I've done well to get to over 24k miles on the originals with 3mm left. So would have got to the end of lease on original tyres. The other week I got a puncture and who knows how long this damage has been on the inside wall of the front tyre.
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How often do YOU check your tyres?
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Is a non repairable puncture in the worn tyre an option?
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I wouldn't be happy with one 3mm and one 8mm on the same axle, very differ braking performance, particularly in the wet.
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Considering it is your safety, is buying a tyre forbidden for a lease car?
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Just stick the 3mm one on the back....
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>> Just stick the 3mm one on the back....
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Controversial !
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Best tyres on the rear ALWAYS regardless of the driven axle..
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You could always pick up a nail in the other tyre ;)
Was at the tip today. Someone appeared to have been dumping plasterboard and left 6 plasterboard nails in close proximity on the floor. Would have ruined someones day for sure. I picked them up and disposed of accordingly :)
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Read this verdict by Michelin a while back on (I think TyreReviews) and it struck me that the company surprisingly offered its opinion despite the fact it might well cost it tyre sales!:
tinyurl.com/yd5hod43
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I'm stock arguing for a replacement due to 3mm tread left. I am arguing because the two fronts will have 3mm and 8mm respectively.
If this was a Volvo AWD it would need all 4 replacing at the same time!
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Forgetting the company involvement I'd change this if it were my own car as like some above I consider changing once tyres reach 3mm.... and if I do take them to 2mm I curb my wet driving enthusiasm. The potential for differential grip in the wet is quite significant between 8mm and 3mm.
I remember from my company car days though they are devils for holding out... often until the legal or not threshold is reached.
Still you can always rely on DSC to help you out.
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>> 1km the new tyre should resolve 500 times and the old one 508 times but
>> it won't if it's on the same axle?!?!
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Why not - it's not a solid axle - there's a differential.
The traditional way of resolving this situation is to shuffle the wheels round and put the odd most-worn tyre as the spare. Then if the situation repeats you could, if you want to penny-pinch, use up the last few mm by running the pair on the front in summer, and then get a new pair before autumn.
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>> The traditional way of resolving this situation is to shuffle the wheels round and put
>> the odd most-worn tyre as the spare. Then if the situation repeats you could, if
>> you want to penny-pinch, use up the last few mm by running the pair on
>> the front in summer, and then get a new pair before autumn.
Do the new pair go on the front or the rear?
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>> Do the new pair go on the front or the rear?
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Naughty, you know that most people know better than the tyre manufacturers, who have spent millions in research and testing. :-)
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Indeed we do. On a front wheel drive car you hardly need tyres at the rear...
www.youtube.com/watch?v=ObY5eaK9e6w
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>> most-worn tyre as the spare.
Car has a space saver spare. If it was a VW it would probably be a full size alloy and I'd have never started this thread.
Last edited by: rtj70 on Tue 12 Sep 17 at 09:36
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When I had a company car I treated it like my own. That meant I drove it sympathetically, washed and polished it, sorted stone chips, bought the manufacturer's topup oil at my own expense, stuck to the service requirements and generally looked after it.
Therefore it used to frustrate me when the "help" desk tried to get tyres to last to 2mm when, if it were my own car, I would change when nudging below 3mm. If I faced a refusal to change "just legal" tyres I used to explain that I was about to drive over the Alps to southern Italy and back over the next fortnight. The tyres would therefore not make the whole trip. Usually worked.
With a more modern car it might be that my TPMS would play up with mismatched radii? Intermittently of course.
Putting my money where my mouth is I now run my own car and changed this year to Cross Climates from standard tyres when fronts were just below 3mm and rears still above 4mm.
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>> With a more modern car it might be that my TPMS would play up with
>> mismatched radii? Intermittently of course.
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My cars TPMS has to have its calibration initialised after pressure adjustments or tyre changes. I assume this is so that it sets a normal rotation ratio between each individual wheel.
Last edited by: Old Navy on Tue 12 Sep 17 at 12:27
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I'd reason that an 8mm and a 3mm is better than 2 x 3mm and get on with it TBH.
What are the rears like? If they are 3-4mm I'd put them on the front and the other two on thae back.
FWIW, and if they are non-directional tyres, I'd probably prefer the 8mm on the nearside - there is usually more standing water near the edge of the road.
The difference in rolling radius is immaterial, unless the car has a sensitive 4WD system.
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>> I'd reason that an 8mm and a 3mm is better than 2 x 3mm and
>> get on with it TBH.
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I wouldn't - you don't want asymmetrical braking at either end. If worn evenly the 3mm would offer more grip on warm dry road due to more rubber contact whereas the 8mm would be much better at clearing standing water.
>> I'd probably prefer the 8mm on the nearside there is usually more standing water near the edge of the road.>>
If you have to live with it I'd agree.
>> The difference in rolling radius is immaterial, unless the car has a sensitive 4WD system.
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Totally!
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Interesting thought experiment HC. The same brake force will be applied to each wheel, but one will have slightly less grip than the other so net friction will be greater on the one with better grip.
I seriously doubt if you would feel any steering pull on a modern road car with negative roll radius steering geometry, and it would almost certainly steer straight. However the moment would still be there - a theoretical potential for a spin, should the rear wheels lose adhesion.
The question is would it matter? Braking on a wet road there is always a chance that one wheel has more water under it than the other and as has been said the ABS and or ESP will come into play. Considering the number of cars running around with mismatched tyres I doubt it would signify.
Comparing a little difference in brake balance across the front with having materially reduced grip at the rear, I'd much prefer the former. I had a Land Rover that when empty would lock the back wheels with careless braking even in the dry, at which point the back would go out one way or the other. This would happen very rapidly in the wet, even with the car travelling in a dead straight line to begin with. That really was dangerous.
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When I used to be responsible for a couple of pool vehicles at work, it was trying to get blood out of a stone whenever you approached the leasing company for new tyres. They refused to change them until they were down to the TWI markings. They even refused to have any wheels balanced that were causing a vibration.
I can remember the ATS manager having a heated argument with the leasing company when I took one of the pool cars down to the local tyre depot. It was all over them not wanting to pay £5 to have 2 wheels balanced. The ATS manager almost lost the will to live and was about to pay for the work himself to save further aggro.
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Part worn tyre on same axle as new... opinions - Lygonos
