Topic: AWD + tire replacement = rude awakening!

[lebowski]

The automatic transmission equipped Subarus are for sure among the pickiest AWD systems when it comes to tires.  The older manual trans models a little less so thanks to "slop" in the center diff, but the AT models use more computerization to assess wheel speeds and slip.  So, even the old non-traction-control models can be fussy, and he newer ones are equally so, or more.

My Highlander's full time AWD is also tire-sensitive, but it's very similar to the Subaru systems.

Sorry John, just seeing this now - thanks again for the insight 

[capriracer]

An interesting story:

Some years back I had a heated conversation with a Volvo dealer over the cost of replacing an AWD system for the second time, because of the difference in tire diameters between the pair they were keeping on the car and the new ones they put on (same make and model tire, but different tire manufacturing plants) until I pointed out the technical service bulletin issued by Volvo that said to replace all 4 tires when doing so.  This information wasn't in the owners manual - and nowhere on the car did it say the car had AWD!

[dkaz]

The automatic transmission equipped Subarus are for sure among the pickiest AWD systems when it comes to tires.  The older manual trans models a little less so thanks to "slop" in the center diff, but the AT models use more computerization to assess wheel speeds and slip.  So, even the old non-traction-control models can be fussy, and he newer ones are equally so, or more.

My Highlander's full time AWD is also tire-sensitive, but it's very similar to the Subaru systems.

Does that mean a spare tire wouldn't work?

[johngenx]

The automatic transmission equipped Subarus are for sure among the pickiest AWD systems when it comes to tires.  The older manual trans models a little less so thanks to "slop" in the center diff, but the AT models use more computerization to assess wheel speeds and slip.  So, even the old non-traction-control models can be fussy, and he newer ones are equally so, or more.

My Highlander's full time AWD is also tire-sensitive, but it's very similar to the Subaru systems.

Does that mean a spare tire wouldn't work?

Until not long ago, all Subarus came with full sized spares.  Even with the "mini" spares, it's my understanding that they're the same outside diameter as the standard tires, just narrower to save space and weight.

[Angry Chicken]

Interesting thread!  I’ve had zero issues at the track running differently worn tires on my AWD TT.  And it is driven hard! 

My front left tire wears quite quickly at Calabogie and I just rotate it to the rear right. I usually end up FL to RR to RL to FR in my normal rotation pattern.  That’s if the tire that was on the FL ever Is lucky enough to see the FR before all tires are worn to the point they need to be replaced.