Whats the official line on 4x4?

[Mx5_csl]

Hi all,

 

I've recently taken delivery of a new Octavia vRS, its the 4x4 DSG model and i'm wondering what the best plan of action will be come tyre change time.  I'm aware advice of old has been to change all 4 tyres on a 4x4 vehicle as to not knacker the couplings, however with the haldex system which is 2wd for most of the time, i'm not sure if that advice still stands?

 

Has anyone been through this / knows the definitive line from Skoda? there is no info in the handbook - i did try asking customer services but the response was rubbish and went no further than advice on using the correct spec tyre!

 

Thanks

[Pmc1]

I didn't own a vrs but a humble 1.9tdi 4x4.

Had it for 12 years and changed tyres in pairs, as in both fronts or rears, as needed. Never rotated the tyres.

Only ever changed all 4 tyres together on one occasion as usually the fronts wore out quicker than the rears.

Haldex and couplings were fine.

[KenONeill]

OK, let's run some numbers using a 235/35R18 wheel and tyre combo. As long as we hold the make and model of tyre constant it doesn't matter whether the tyres are omni-directional, uni-directional or asymmetric.

 

18" diameter is 9" radius * 25.4 mm to the inch gives 228.6 mm wheel radius.

 

235/35 gives 235mm * 0.35 nominal tyre wall height for 82.25 mm.

 

Add those together and you get 310.85 mm nominal rolling radius.

 

Typically you have about 6 mm usable tread depth from new to "only just legal", so this gives us 6/311 for 1.9% difference in rolling radius between brand new and worn out tyres.

[Gazdok]

You do not have any problems with the Haldex Gen 3 and upwards. The old pure hydraulic Haldex was susceptible to differently worn tyres.

I have a 4x4 and rotate when I go back from summer to winter and vice versa. I rotate front to back and backs forward cross wise.