New tyres before geo?
New tyres before geo?
Author
Discussion

Podro

Original Poster:

172 posts

178 months

Friday 22nd June 2012
quotequote all
Current tyres have done 10k miles and are 7 year old MPS (car is 996 Turbo S). Would you replace these before a geo set up?

Tyre Inner Middle Outer
Front Nearside 5.2 5.9 4.8
Front Offside 4.5 5.7 5.5
Rear Nearside 3.8 4.6 4.2
Rear Offside 4.3 4.8 3.8


They clearly have life in them, but advice seems to say "they are old so replace them" and "they are not worn evenly so will affect a geo set up".

chris7676

2,685 posts

245 months

Friday 22nd June 2012
quotequote all
Nope, you geo won't be different with new tyres (3mm of ride height difference due to the new tyres tread can be disregarded).

Pickled Piper

6,450 posts

260 months

Friday 22nd June 2012
quotequote all
An experienced Tech will also find the wear patterns on the old tyres very usefull when diagnosing any geo problems.

pp

Matt Seabrook

563 posts

276 months

Friday 22nd June 2012
quotequote all
Geo will not be affected due to your tyres. Handling will though. On a high performance car like yours I would want some new boots on as the tyres have likely age hardened

Podro

Original Poster:

172 posts

178 months

Friday 22nd June 2012
quotequote all
anonymous said:
[redacted]
I like your thinking biggrin

Costco can do a full set of MPS2 N3's for £806.34 'till 1st July so that was also influencing my thinking and that my current one's have probably 'hardened'.

Think I've made my mind up...

rog007

5,821 posts

249 months

Friday 22nd June 2012
quotequote all
Podro said:
Current tyres have done 10k miles and are 7 year old MPS... but advice seems to say "they are old so replace them"
yes

sportsandclassic

3,774 posts

243 months

Friday 22nd June 2012
quotequote all
chris7676 said:
Nope, you geo won't be different with new tyres (3mm of ride height difference due to the new tyres tread can be disregarded).
Your geometry will always be different on new tyres.


chris7676

2,685 posts

245 months

Friday 22nd June 2012
quotequote all
sportsandclassic said:
chris7676 said:
Nope, you geo won't be different with new tyres (3mm of ride height difference due to the new tyres tread can be disregarded).
Your geometry will always be different on new tyres.
Why would that be the case, except for what I mentioned ?

sportsandclassic

3,774 posts

243 months

Friday 22nd June 2012
quotequote all
chris7676 said:
Why would that be the case, except for what I mentioned ?
The tyre sits differently on the rim as it is a new straight tyre not worn to the original camber like the old tyre has. You do a geometry, then fit some new tyres and you will see the steering wheel will be off centre.

Seen this 100 times before, people that do wheel alignments on old tyres then fit new ones..... you are wasting everyones time.

Mike

LaurasOtherHalf

21,429 posts

221 months

Friday 22nd June 2012
quotequote all
sportsandclassic said:
chris7676 said:
Why would that be the case, except for what I mentioned ?
The tyre sits differently on the rim as it is a new straight tyre not worn to the original camber like the old tyre has. You do a geometry, then fit some new tyres and you will see the steering wheel will be off centre.

Seen this 100 times before, people that do wheel alignments on old tyres then fit new ones..... you are wasting everyones time.

Mike
+1 there's no point?

plus 7 year old tyres? not on my car thank you very much

Matt Seabrook

563 posts

276 months

Sunday 8th July 2012
quotequote all
For the OP thought I would do a before and after. Old to new tyres. Your tyres dont have dissimilar wear to my Cayman so thought it would be an idea to let you know that if you tyres dont have large wear differences from inside to outside it's worth having an alignment done if you dont plan to chuck your tyres away soon.

This has the tread depths written on the sheet for comparison.



Now after a new set of tyres fitted you can see that almost no difference is measured on the before and after.



Dont get me wrong if you have tyres with bad wear patterns on them ie large differences inside to outside it would not be wise to align the car with the old tyres on. Your figures are not too bad so had the tyres not been old I would have checked the alignment on those tyres.

Hope this helps.

Podro

Original Poster:

172 posts

178 months

Monday 9th July 2012
quotequote all
Hi Matt,

Thanks for posting this information; good to have some real data. Since starting the post I have had 4 new MPS2's fitted courtesy of Costco and I'm just waiting to get the geo set up. Given that I don't think the car has been geo'd before in 7 years I'm looking forward to seeing the difference biggrin !

Thanks, Paul.

Matt Seabrook

563 posts

276 months

Monday 9th July 2012
quotequote all
No problem wink New tyres on their own should feel better if nothing else. Getting the geo done should also improve the handling if yours isn't great to start with.

P.s. let the tyres run in for a few hundred miles will help them last and grip better before you give it what for. biggrin