Tires: one new tire on an awd vehicle, worst case scenarios, nissan murano

Question
Dear Barry,
I recently got a flat and replaced one tire on my 06 Nissan Murano AWD.  The other tires have approx. 6/32 (using the penny method) of tread left.  Will this damage the transmission?  Do I need at least one more new tire for balance?
Thanks for your time and advice.

Answer
Mark,

This is a question you need to ask Nissan.  They should know what the tolerances are.

Because there are so many types of AWD systems and because each of these systems has a different level of sensitivity to tire diameter, tire folks - like myself - only work with worst case scenarios and develop simple easy to remember rules based on those scenarios.

I know that some Subaru's require tires to be within 3/32nds of WEAR of each other, in order to prevent their AWD system from failing.  This means that not only is replacing a single tire out of the question, but merely lack of rotation is enough to cause damage.  

The above has now become the basis of the rule:  On AWD vehicle, tires should be replaced in sets of 4.

Does that apply in your case?  I don't know, but Nissan does!