Will different tread depths front vs rear harm AWD system on an R

[PlaidDad]

I have the same issue now with both my summer and winter tires - 3 good tires with about half their tread left, 1 that is trashed. Replaced the trashed summer tire in kind now have one new and 3 middle aged, I understand this is not ideal.

The question is whether running two new tires of the same model and size as the remaining two used tires will cause AWD system damage, if I run the two new tires at the same end of the car. The guy I spoke with at Tire Rack thought anything over 2mm of tread depth difference between old and new would be an issue, and that traction control might activate.

Input welcomed.

 

[krs]

Audi service manuals say "rolling radius of all 4 tires must remain the same" or within 4/32-inch of each other in remaining tread depth.

But I haven’t been able to find anything that specific mentioned for VW, other than generalizations.

 

[tigeo]

No - it's fine. Open diffs and Haldex...there is nothing to harm.

 

[tigeo]

Audi service manuals say "rolling radius of all 4 tires must remain the same" or within 4/32-inch of each other in remaining tread depth.

But I haven’t been able to find anything that specific mentioned for VW, other than generalizations.

For Torsen center diff systems (like my B5.5 Passat W8)....Haldex with open front and rear diffs this shouldn't matter and certainly won't harm it.

 

[krs]

For Torsen center diff systems (like my B5.5 Passat W8)....Haldex with open front and rear diffs this shouldn't matter and certainly won't harm it.

Cool, good to know.

 

[hans611]

Want to add that the hadlex control unit logic engages the clutch based on the difference in wheel speed between the front and rear tires... @krs is on to something.

I would not want them too mismatched.... its very sensitive, it reacts to 1-2rpm differences....

 

[tigeo]

Want to add that the hadlex control unit logic engages the clutch based on the difference in wheel speed between the front and rear tires... @krs is on to something.

I would not want them too mismatched.... its very sensitive, it reacts to 1-2rpm differences....

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Sure, but the point is it isn't hurting it...it may just engage it little more/less than if they all matched.