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Discussion summary
YOUR RESEARCHWhich tyre size is correct?
Leading reported evidence
Install are 225/40-18 and 285/30-18 conti sport contacts
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Performed · outcome unconfirmed · Original poster
The tyres currently fitted are 225/40-18 and 285/30-18 Conti Sport Contacts.
Leading evidence: 'Install are 225/40-18 and 285/30-18 conti sport contacts' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Install are 225/40-18 and 285/30-18 conti sport contacts' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
I'll be sticking to the 225/40-18 & 285/30-18 currently fitted - only this time going for Mich Pilot Sports.
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I have the sport classic split rims on mine and are fitted with
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Performed · outcome unconfirmed · Original poster
I have a 1999 Carrera 4 on which the previous owner had replaced the 17" rims with 18" Porsche/BBS split rims which I think are called Sport Design or GT3 style alloys.
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Some were 17" which is often why they were replaced with later wheels and tyres.
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I have a 1999 Carrera 4 on which the previous owner had replaced the 17" rims with 18" Porsche/BBS split rims which I think are called Sport Design or GT3 style alloys.
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Suggestion
I don't know exactly why Porsche changed the spec, but I do know it's fine to run 265 on the rear if you want to, they are within spec of the 10J alloy.
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Suggestion
I don't know exactly why Porsche changed the spec, but I do know it's fine to run 265 on the rear if you want to, they are within spec of the 10J alloy.
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I have a 1999 Carrera 4 on which the previous owner had replaced the 17" rims with 18" Porsche/BBS split rims which I think are called Sport Design or GT3 style alloys.
The rims are 8J x 18 (front) and 10J x 18 (rear).
The tyres currently fitted are 225/40-18 and 285/30-18 Conti Sport Contacts.
However the owners manual states 265/35-18 for the rears for a 10J rim (which I have) and 225/40-18 for the front for a 7.5J rim (which I don't have!). I think on facelifted cars a 285/30 was recommended- why the change?
So it would appear either way the tyres fitted may be wrong.
The current tyre sizes looks fine - not pulled out to the rim, and conversely not overhanging. But would I be correct in replacing them with the same size?
Incidently the tyres have been replaced by an OPC in the past - surely they would have fitted the correct size?
I need to replace all the tyres pretty well immediately, so any help would be appreciated.
Cheers
Bill
HI Bill,
If I remember correctly, you have facefilted MY2001 996 tyres and wheels on a pre-facelift MY1998 car. Some were 17" which is often why they were replaced with later wheels and tyres.
Pre facelift cars were 7.5J front with 225x40 tyres. Rears were 265x35's on 10J wheels.
If they,re not rubbing on full lock, during compression or rebound you should be OK.
:thumb:
This will probably be blown out of the water by one of our more technically aware members but in my opinion I think you're OK. :frustrated:
I have the sport classic split rims on mine and are fitted with
225 40 18 and 285 30 18
the rears were 265 30 18 as per manual but the slightly wider tyres fit perfectly and give a little bit of protection from kerbing :thumb:
TB
Ditto whats been said before, the 285s at the back are good. I actually think the 265 are slightly too small, the tyre wall angles in from the rim to road where as the 285 is straight with some added rim protection.
Good to know this info as I'm about to replace my 285s and was wondering if the 265s were more cost effective? Seems as though staying with the 285s is more sensible owing to greater rim protection and as everyone seems to be suggesting greater aesthetics.
~ Maxie
Maxie, I did all my rim damage whilst on 265s, haven't done anything (touches wood) since fitting 285s, plus more rubber on tarmac at the back end must be a good thing
I used to have a four wheel drive mitsubishi GTO, i remember I had to get the tyres sizes spot on to avoid damage to the transmission ( viscous coupling i think ) apparently a slight difference in rolling circumfrence can cause problems on four wheel drive cars, any views on this for my carrera four ?
This:
The rims are 8J x 18 (front) and 10J x 18 (rear).
The tyres currently fitted are 225/40-18 and 285/30-18 Conti Sport Contacts.
is the correct tyre size for the wheels.
7.5J front was the pre-facelift spec, 8J was the post facelift.
I don't know exactly why Porsche changed the spec, but I do know it's fine to run 265 on the rear if you want to, they are within spec of the 10J alloy. Personally, I'd run 285s.
It's also fine to run 8J on the front of pre-facelift cars.
PS - consider a switch to Michelin PS2s, but swap front and rear at same time if a 4WD model.
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