Thread: max allowable difference in tyre circumference

There is very little difference in the rolling diameter of a tyre between new and worn out. The belts immediately under the tread are what determine the rolling diameter, so don't worry too much about the different amounts of tread.

How much difference in tyre diameter is ok?

I'd be more worried about the gearing , i find 32" are fine on my tdi auto but not sure about 33's on stock gears.

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I have a 4.6 in the D1, so I'm hopeful the extra mumbo will be able to handle the higher gearing. I'll go back to 31s for towing though!

Originally Posted by aussearcher

I have a 4.6 in the D1, so I'm hopeful the extra mumbo will be able to handle the higher gearing. I'll go back to 31s for towing though!

For play tyres they will be fine.

Further to bee utey's point above that tread wear is not a significant factor in rolling circumference, I measured the tyres today, all inflated at 40psi. The circumference of the "as new" tyre was 2640mm, the next best 2590mm (98.1% of the "as new" tyre), and the others all 2570mm (97.3%).
So a 2.7% difference between best and worse, on tyres that will spend most of their lives in the slippery stuff. I think that the diffs can cope with this!

Originally Posted by aussearcher

I think that the diffs can cope with this!

Gives them something to do..