Tyre Tread Depth

[venomx]

At which depth do you guys replace tyres ?

Front Nearside is 5.1mm
Front offside is 5.5mm
Rear nearside is 7.5mm ( this tyre was fitted a month ago )
Rear offside is 6mm

I know they don't need doing yet but I would like to know what you guys think ? Thanks

 

What about rotating tyres, is this mainly to get the most out of them or is it mainly for saving pennies by not having to replace them as often ?

[Auris James]

Around 2.5-3.0mm for me.

Or on age if perished. James👍

[FROSTYBALLS]

When the tread gets under 3mm. 

Pros and cons re tyre rotation. Rotation evens out the wear, but this may mean having to replace all four tyres at the same time. 

As regards changing just two tyres, tyre industry recommendations are that the two tyres should be on the same axle, and that new tyres are put on the rear.

[Roy124]

42 minutes ago, FROSTYBALLS said:

 Rotation evens out the wear, but this may mean having to replace all four tyres at the same time. 

Another way of expressing this is you start with 4 good tyres that continually get worn to a minimum grip all round. 

Or you always have two good tyres on the back. 

[venomx]

Is this where to check your tyre tread ?

 

 

I use one of these tools to check.

 

[MikeSh]

5 minutes ago, venomx said:

Is this where to check your tyre tread ?

No. The TWI bars indicate the minimum permitted tread depth (1.6mm?) when they are flush with the tyre surface.

You check anywhere else to get the actual depth, but it will usually be the outer edges that show the least, so concentrate on there a bit.

[venomx]

20 minutes ago, MikeSh said:

No. The TWI bars indicate the minimum permitted tread depth (1.6mm?) when they are flush with the tyre surface.

You check anywhere else to get the actual depth, but it will usually be the outer edges that show the least, so concentrate on there a bit.

OK I understand thanks.

[Starensis]

2 hours ago, FROSTYBALLS said:

When the tread gets under 3mm. 

Pros and cons re tyre rotation. Rotation evens out the wear, but this may mean having to replace all four tyres at the same time. 

As regards changing just two tyres, tyre industry recommendations are that the two tyres should be on the same axle, and that new tyres are put on the rear.

I had 2 new fronts fitted at local dealer. I asked them to fit on rear and move rear to front - they refused to do it! 🤷🏻‍♀️

[Ashfaqur]

46 minutes ago, Starensis said:

I had 2 new fronts fitted at local dealer. I asked them to fit on rear and move rear to front - they refused to do it! 🤷🏻‍♀️

Last month, I had two front tyres replaced after having purchased an approved 68 reg Auris hybrid from a Toyota dealer. Upon inquiring if they were going to put the new ones at the rear and the older (with pretty good tread) on the front, I was advised that that wasn't considered important any more. 

Coming from a dealer, I took it as correct. I hope they are right. 

[MikeSh]

7 minutes ago, Ashfaqur said:

I was advised that that wasn't considered important any more. 

I imagine that ABS and ESC have changed the game somewhat.

[flash22]

51 minutes ago, Starensis said:

I had 2 new fronts fitted at local dealer. I asked them to fit on rear and move rear to front - they refused to do it! 🤷🏻‍♀️

TPMS once registered it knows what location that sensor in, shuffling the wheels will require a relearn period after reset - dealers don't have time to mess with it

[FROSTYBALLS]

Looking at their websites, Michelin, Goodyear (and Dunlop as they are owned by Goodyear in Europe), Kumho, and Uniroyal still say fit new tyres to the rear axle. 

[Stopeter44]

52 minutes ago, FROSTYBALLS said:

Looking at their websites, Michelin, Goodyear (and Dunlop as they are owned by Goodyear in Europe), Kumho, and Uniroyal still say fit new tyres to the rear axle. 

Counter intuitive, maybe, but that is apparently what is required.

[venomx]

13 hours ago, FROSTYBALLS said:

and that new tyres are put on the rear.

If just replacing the front two, and not the old rear two... Why would the new tyres be put on the rear if the front ones get worn down quicker ? Surely the tyres will wear down more evenly if you put the new ones on the front

[Stopeter44]

Like I said it's counter intuitive, but I expect it's to ensure that, with time, you don't have bald tyres at the rear and that the rear of the car adheres better in, let's say, "violent" manoeuvres.

Tyres wear down unevenly, all other things being equal. The fronts more than the rears, and in the UK the left front tyre more than the others, followed by right front, left rear and right rear. Which is why periodic rotation of tyres is advised. Why the left front more than the right front ? Because of roundabouts. In the UK you turn right more than you turn left. In LHD countries it is RF, LF, RR, LR.

[TonyHSD]

3 hours ago, venomx said:

If just replacing the front two, and not the old rear two... Why would the new tyres be put on the rear if the front ones get worn down quicker ? Surely the tyres will wear down more evenly if you put the new ones on the front

Your tyres are all mixed thread depth, make and models most likely, my best advice is to replace all 4 with new good tyres and do wheel alignment, then you can rotate front to rear with every service to maintain equal thread wear and replace again all 4 after they get close to wear indicators shown on your picture or after 5 years. Once the tyres get older their properties  changed to the point that they may become even dangerous. Rubber it’s a “life material” and ages with time , make sure also the new tyres are no more than a year or year and half old when fitted. Changing only 2 tyres or 1 tyre it’s a false economy and definitely not a smart choice. Tyres are most important part of your car along with your brakes and the only contact between the car and the road. If it’s me I will buy 4 new all season tyres and I will know that next week when temperatures goes down to freezing and some snow arrive I can still take my car out and safely enjoy driving it on white roads and perhaps have some fun 🏎🏁👌

[Stivino]

It is nothing to do with wear rates, it's to do with grip.

From Uniroyal's website, other manufactures will say the same;

'If you replace old tyres with new tyres and this does not apply to the whole set, there comes the question: Do you fit the new tyres at the front or back? Regardless of the drive type, we recommend not fitting the better tyres at the front, but always fitting them at the back. The reason is simple: The rear axle ensures the tracking stability of a vehicle.'

[Stopeter44]

11 minutes ago, Stivino said:

The reason is simple: The rear axle ensures the tracking stability of a vehicle.'

Which is what I was trying to say.

[bathtub tom]

4 hours ago, venomx said:

Surely the tyres will wear down more evenly if you put the new ones on the front

They probably will, but I understand the reasoning for putting new tyres on the rear is you're more likely to understeer off the road in an emergency. Fitting new tyres to the front means you're more likely to oversteer off the road. Average drivers can deal with understeer, but less likely to be able to cope with oversteer, I put new tyres on the front to give better traction and prefer to go through the hedge backwards, that way I don't see what I'm about to hit. Zaphod Beeblebrox had the same idea with his sunglasses!

[bathtub tom]

3 hours ago, Stopeter44 said:

Because of roundabouts. In the UK you turn right more than you turn left. In LHD countries it is RF, LF, RR, LR.

I don't follow that. Assuming every journey ends up a reciprocal, then doesn't it follow you turn an equal number of times each way?

I understood the front nearside wears most because of road camber and you're effectively always turning slightly right to counteract, putting most stress on the front left.

[Stopeter44]

23 minutes ago, bathtub tom said:

I don't follow that. Assuming every journey ends up a reciprocal, then doesn't it follow you turn an equal number of times each way?

I understood the front nearside wears most because of road camber and you're effectively always turning slightly right to counteract, putting most stress on the front left.

• Roundabouts : You go around the roundabout counter clockwise, on the return journey ? 🤔
• Road camber : Now that's a good point, I was quoting my tyre specialist, but I think what you say here must come into it 🤙

[Stivino]

Roundabouts;  to use a roundabout you go left, right then left.  Therefore the lefts and the rights cancel each other out.

I put it to the forum that 'roundabout syndrome' is an urban myth.

[Stopeter44]

I now think road camber that has the most influence on tread wear so I have been persuaded, I was just repeating what my tyre guy had told me.  OTOH, this article affirms it's roundabouts 1st then road camber

Why do front tyres wear differently

Edited November 18, 2021 by Stopeter44
link

[MikeSh]

4 hours ago, bathtub tom said:

Average drivers can deal with understeer, but less likely to be able to cope with oversteer,

True for older cars. But for modern cars with ESC it's not so much of an issue, which may be why some dealers are saying it's not necessary to put new on the back and move the backs to the front.

New on the back has been the advice for as long as I can remember, but it may be a 'rule' that has had its day.

[TonyHSD]

New tyres on the rear seems to me purely business oriented advice plus “idiot proof” which also works in interest of business and insurance. Sticking older tyres on the front will require yearly change with new tyres as those get more of the work. Most cars after my 2001 has ABS+EBD which ensures proper split between front and rear axle brake forces and when in extreme situations like hard braking the car system helps inexperienced drivers to maintain straight direction. For the aquaplaning., that happens 95% while the car is under load, under acceleration and hitting a deep waters, here it’s only dangerous for cars with RWD which will spin it’s rear end causing oversteer and lost of control. Older school rules are way more sensible to put the better tyres on the drive axle to ensure grip to keep you going and driving sensibly preventing extreme situations will take you safely to your destination. The whole point of tyre rotation is to wear all 4 tyres evenly and replace all 4 together with matching new tyres set which is the best and safest thing to do about tyres and your car.