4X4 - Necessary to replace all four tyres?

[AudiMan9000]

Let’s say you’re driving along then pop, you have gone over a nail in the road and you now have a flat tyre.

If your vehicle is a 4 wheel drive or all wheel drive, is it essential that you fork out for FOUR new tyres?

[rog007]

Firstly, many punctures caused by nails can be easily repaired.

If it’s un repairable, then one would usually purchase a new tyre exactly the same as the other 3.

If said puncture happened at around the time when you were due to replace all 4 tyres, then you might consider it.

Equally, if the damaged tyre in question was no longer available, then again, you might want to consider replacing all 4, remembering that tyres fitted on the same axle must also share the same structure - it is not permissible to mix directional and asymmetric tyres.

Otherwise, you just replace the one.

[Rob_125]

I'm guessing this is reference to transmission windup? And difference in rotational speed. Worst case id replace a pair (fore or aft). But it might depend if you have fancy electronic diffs ectect.

[Smint]

I rotate tyres on my AWD cars religiously so always buy sets of 4.
If at say 5mm remaining i had one unrepairable puncture i'd try to find a part worn of similar tyre type to see the set out, at 3mm i'd already be looking for another set.

No point in putting the various diffs through extra wear having to make constant adjustments due to one or more tyres haing a different tread depth.
I know others do this, just not something i would do.