tyre depth...

Author
Discussion

marky999

Original Poster:

221 posts

143 months

Wednesday 6th February
quotequote all
Hi, got new rear tyres for my 991.2 Carrera 500 miles ago, fitted by my OPC (20 inch wheels). They had them in stock and fitted them when car was in for service. Just gone in again for a minor job and in their health check they say the rear tread is now 6.1mm.

They were over 3mm when I swapped them after 17000 miles, so it seems surprising to me they would be at 6.1mm, just 500 miles after being fitted new but I don't know what tread they start off at new. I just do general easy driving...

Does anyone know if new tyres wear more at the start? The original FRONT ones are still on 5.1 and 5.5mm after 17000 miles. But they are a different size I think and perhaps have a different new tread depth to the rear?

Thanks and apologies if this is confusing (and a tad boring).

Edited by marky999 on Wednesday 6th February 09:34

Porsche911R

16,242 posts

203 months

Wednesday 6th February
quotequote all
report back when they are on 2mm.

I just had new tyres before a service ie 1 day before and I had a tyre inspection, it was in the 6mm range.

marky999

Original Poster:

221 posts

143 months

Wednesday 6th February
quotequote all
Porsche911R said:
report back when they are on 2mm.

I just had new tyres before a service ie 1 day before and I had a tyre inspection, it was in the 6mm range.
Thanks!

mr pg

1,417 posts

143 months

Wednesday 6th February
quotequote all
You've bought a 911 and you just do general easy driving? You're missing out.

SHIFTY

505 posts

174 months

Wednesday 6th February
quotequote all
Worth checking the month and year date stamp on the tyre, old tyres wear more quickly and should be replaced 5 years fron the date stamp.

Would not expect an OPC to only carry old tyres.
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ellroy

5,702 posts

163 months

Wednesday 6th February
quotequote all
If i recall new should be about 8mm?

DJMC

2,223 posts

41 months

Wednesday 6th February
quotequote all
New tyres have 8mm usually. So you've worn 2mm off in 500 miles, or they weren't new (unlikely).

What make & model of tyre?

Have you been doing doughnuts?

boxsey

3,287 posts

148 months

Wednesday 6th February
quotequote all
ellroy said:
If i recall new should be about 8mm?
Depends on the tyre and manufacturer. You won't get 8 mm on low profile sports tyres that are used on Porsche sports cars. e.g. from what I've read the Michelin PS4 comes with about 7 mm when new.

SV_WDC

223 posts

27 months

Wednesday 6th February
quotequote all
You could also ask where the reading has been taken. Most (good) tyre places I've been to give you a read-out of three points of the tyre for each corner; either edge & the middle.

It might be that the geo or wheel balancing is off & causing the tyre to wear excessively at the point where the reading was taken.


marky999

Original Poster:

221 posts

143 months

Wednesday 6th February
quotequote all
Thanks guys. Pirelli P Zero, 305 30 ZR20 103Y. Fairly sedate driving for which I should be duly castigated smile

I also had the alignment done 500 miles ago at the service.

I've called OPC to ask them to check this out...all comments have been very helpful thank-you.

DJMC

2,223 posts

41 months

Thursday 7th February
quotequote all
marky999 said:
Thanks guys. Pirelli P Zero, 305 30 ZR20 103Y. Fairly sedate driving for which I should be duly castigated smile

I also had the alignment done 500 miles ago at the service.

I've called OPC to ask them to check this out...all comments have been very helpful thank-you.
Can't have worn 2mm in 500 miles. Those things are made of steel!!


996Targa

8 posts

84 months

Friday 8th February
quotequote all
Because of similar concerns, the last time I bought a set of 18" PS2 N3 I measured them before they were fitted.

PS2 has 3 grooves. The fronts were 8/ 8/ 8. The rears were 7/ 7/ 6 out to in, both tyres.

vernz

150 posts

68 months

Friday 8th February
quotequote all
boxsey said:
Depends on the tyre and manufacturer. You won't get 8 mm on low profile sports tyres that are used on Porsche sports cars. e.g. from what I've read the Michelin PS4 comes with about 7 mm when new.
Just had a full set of 235/35/19 MPS4's tyres fitted to my Type R. I checked the tread depth with my gauge and they were 8mm. The last two Conti sport contact 6's I had on the front were measured with the same gauge as 7mm from brand new.

If I wear the new tyres down to 2mm, straight away it seems that I'm going to get 20% more wear from the Michelins.

BertBert

12,293 posts

149 months

Friday 8th February
quotequote all
Depends on the wear rate!

vernz

150 posts

68 months

Monday 11th February
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BertBert said:
Depends on the wear rate!
It certainly does and in the case of the Conti sport 6's the wear rate is horrendous.

As mentioned, they came with 7mm tread and the MPS4's came with 8mm from new which is why I mentioned that this is 20% more wear, assuming wear rates are the same, which in the case of the Conti's is certainly not the case.

The Conti's are OEM on the Civic type R and I've seen long term reviews where the tyres were gone at 3000 or 6000 miles. Generally the life span for mixed relatively moderate driving is 10k at best.

According to the Michelin website they are stating an increase in wear for the PS4's over the Conti's of 13000 miles, which is bonkers, especially when every review has the Michelin equal or better in all other performance measures.

At only a bit below the cost of the Michelin's I really can't see an argument for these over the Michelin's or the relatively cheaper Goodyear F1's




Rockster

1,485 posts

98 months

Tuesday 12th February
quotequote all
marky999 said:
Hi, got new rear tyres for my 991.2 Carrera 500 miles ago, fitted by my OPC (20 inch wheels). They had them in stock and fitted them when car was in for service. Just gone in again for a minor job and in their health check they say the rear tread is now 6.1mm.

They were over 3mm when I swapped them after 17000 miles, so it seems surprising to me they would be at 6.1mm, just 500 miles after being fitted new but I don't know what tread they start off at new. I just do general easy driving...

Does anyone know if new tyres wear more at the start? The original FRONT ones are still on 5.1 and 5.5mm after 17000 miles. But they are a different size I think and perhaps have a different new tread depth to the rear?

Thanks and apologies if this is confusing (and a tad boring).

Edited by marky999 on Wednesday 6th February 09:34
My info is the tread depth for the tires you are using -- which you posted in another post -- is 9/32" or around 0.281 inches or around 7.1mm.

Provided the tread wear measurement is to be believed, to wear 1mm in 500 miles is not good. With my Boxster and Turbo I could get 20K miles (in the case of the Turbo nearly 23K miles and the tires still had enough tread to qualified for one tire being replaced under a road hazard coverage!).

But this good tire life required the cars be probably aligned. In one case with my Turbo I went through a set of rear tires in around 8K miles when the alignment was off. The tires were worn to the belts on the inside edges. This a sign toe is way out.

marky999

Original Poster:

221 posts

143 months

Thursday
quotequote all
So grateful for the feedback guys. So useful. This forum excels again smile