Front tire matching 2005-2012

[curvecrazy]

Hi.  I’m new here.  Quick question about tire matching.  The new AWD cars require tread depth tire matching in order to not mess up their AWD systems.  
I have an 05 Pathfinder LE 4WD version.  This has the drive selection for 2WD, AWD, 4WD and 4WD LO.  
I don’t use anything but 2WD.  I understand that, in 2WD the rear wheels are active and that it’s best to tread depth tire match that rear axle.  But, since the front is not engaged, is tread depth tire matching required in the front if only 2WD is ever used?  
I know best practices and all that, but I have a bad front tire and the other side is well worn.  I was thinking of just running the new full size spare.  

[Trevor]

I would imagine if the front hubs are manually unlocked then it should be fine but if auto locked hubs then potentially the different rolling diameter would affect the transfer box, etc....so probably worth ensuring all four tyres are same tread depth as near as possible

[curvecrazy]

My thoughts exactly.  I’m thinking that the 05-12 Pathfinder LE’s, when in 2WD, do not have the front transfer case engaged at all.  
 

There’s no hub lock or unlock on these.  Unless selecting 4WD is what you’re referring to by manually locking the hubs.  
 

AWD is a confusing on this vehicle.  I don’t think that the hubs are technically locked, but they’re obviously engaged, and the drive is put to the front by “The System” when it senses “Slip” I guess.  And if your front tires are mismatched, it might sense slip continuously.  
 

I guess that I could put the truck up on the lift, start it and engage “Drive”(2WD), and just see what’s spinning.  I would assume that the forward drive shaft always spins, but that the transfer case is not engaged.  
 

Another way would probably be to put on the new front tire on the front paired with the used front tire and go drive.  If it’s a problem, the “VDC” and “Slip” lights would probably come on.