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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH996 C4S understeer cured
Leading reported evidence
Replace front tyres
Performed · outcome unconfirmed
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0
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Performed · outcome unconfirmed · Original poster
Front tyres were changed due to a flat spot causing vibration at 70 plus MPH so plenty of grip left.
Leading evidence: 'Replace front tyres' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace both' (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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Suggestion
If is more than that then I would say change both.
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Suggestion
If one damaged rear tyre needs replacing , do you have to replace both tyres to keep things symmetrical?
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Suggestion
If one damaged rear tyre needs replacing , do you have to replace both tyres to keep things symmetrical?
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Suggestion
I will point out the fact it's a really really really bad idea to run different front and rear tyres on a 4wd car.
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911uk: 1 discussions
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Interesting... Is that because the front tyres were gone and now the new ones have better grip or is it the combination as each set or tyres have different characteristics... :?:
Front tyres were changed due to a flat spot causing vibration at 70 plus MPH so plenty of grip left. My view is that the PS2's are very grippy, especially impressive in the wet, the Rosso's on the rear less so. This has resulted in a much more neutral steer characteristic to the car.
There is one particular bend on my commute that will expose any such weakness in a car and my C4S used to understeer so badly around this that I could only cancel it out by tapping the brake pedal repeatedly.
Now the car goes around like its on rails - an incredible difference.
I will point out the fact it's a really really really bad idea to run different front and rear tyres on a 4wd car. Generally each brand tyre has a different circumference despite having the same "size" and this variance can wear your center differential as there will be a constant speed difference between the front and rear. I'm sure the manual will says this somewhere as well.
I have made this mistake on past cars and in an extreme case the drivetrain in the car was banging loudly every 50 meters odd. This was as the tension in the system "wound up" and let go, the drivetrain would bang in release. Now just because that's not happening doesn't mean you're not prematurely wearing the center differential....
Just something to think about.... and may never eventuate.
Regards,
JEff
Not a good idea to mix them as Jeff says.
If you want a better solution do as I suggested and get the car's geo. sorted. By default, they understeer but this can be dialled out safely without resulting to running different tyres.
I wonder how they will wear and whether the benign effect will persist?
Sounds like the tyre characteristics are masking a problem which really needs fixing, they don't understeer that badly.
Tyre replacement on rear of C4S
If one damaged rear tyre needs replacing , do you have to replace both tyres to keep things symmetrical? The undamaged tyre has been only a few thousand miles.
Re: Tyre replacement on rear of C4S
If the tyre is identical and you have only 1-2mm difference in the thread then it should be ok. If is more than that then I would say change both. (2mm is about 25% of the max thread as new tyres come with 8-9 mm)
Theo
