New tyre tread depth.

[John]

I've always understood new tyres are 8mm.

Can this vary i.e. they won't always be exactly that?

I've seen "around 8mm for new tyres a lot" so I am presuming not.

My car was in for warranty repairs with MB and they send you a video with the tyre depths.

Allowing for a small amount of error, my new GYEF1A5s were 7mm and 7.3mm respectively.

They've only been on the car just over a week and have done a couple of hundred miles.

So I was a little surprised but new tyres are not something I've ever measured the tread depth before because... well you assume if they are new they will be 8mm.

 

[daveenty]

They vary quite dramatically John, from not much over 7mm to nearly 9.

As for MB measurements, a large pinch of salt required. Pure guesswork I'm afraid.
When I had the taxi, they told me that my rear pads were 60% worn. The same read pads I'd fitted the day before it went in for a service. Not even 10 miles travelled on them.

 

[John]

I suppose the cynic in me (moi?) thinks they do it quick and it's in their interest to read low.

That just sounded a lot out to me even allowing for any **** piggery but it's good to know they could well be that from new anyway.



They did mention the brake pads/discs but I would wait for a trusted inde to tell me they are low!

 

[AMGeed]

It really is bad practice to advise certain items are close to worn out when the exact opposite is true.
It only takes a few who believe everything they are told and the dealers are making money.

In Dave's case above, I think I'd have to have a word with the tech who allegedly checked those pads. Failing that, the service manager.
All confidence in that particular dealer would be lost if it happened to me.

 

[markjay]

My experience is that new (summer) tyres are either 7mm or 8mm when new.

Given that the manufactures recommend tyres should be replaced at 3mm tread depth, the effective service life of a tyre is 4mm to 5mm.

So for example a tyre that started its life with 8mm and is now 5mm, is in fact 60% worn i.e. it has used-up 60% of its service life.

 

[Oldlae]

The last Michelins I fitted to my 'Munich airport taxi' (which will be the last ones I buy for this car) appeared to be half worn when new, and proved not to be good value, the rears wore out in 9,000 miles and the fronts in 18,000. Not good value.
Tony

 

[190]

More tread depth creates more heat due to the blocks flexing so sometimes tyres of a higher speed rating have less tread depth than the same tyre of a lower speed rating. I've measured brand new V rated tyres accurately with a Vernier depth gauge at 7.4mm.

 

[John]

Given that the manufactures recommend tyres should be replaced at 3mm tread depth, the effective service life of a tyre is 4mm to 5mm.

So for example a tyre that started its life with 8mm and is now 5mm, is in fact 60% worn i.e. it has used-up 60% of its service life.

Yes, I work with 8mm down to 2mm as the service life. So if the tyres are down 1mm new that's down getting on for 20% less already.

As it happens, I checked the date codes and they are both the same at week 31 this year so must just be as it is!

Thanks folks.

 

[Bobby Dazzler]

I’ve always assumed 8mm but i’ve Only ever measured it once. Well the fitter did. I think the Continental winter tyres I bought were 9.6mm. Coincidentally, just had a set fitted today.