Say I get a flat and have to use my full size spare. Toyota warranty says I needs a rotation every 5000 miles. In case of a flat mount, spare and get flat tire fixed by a toyota dealer as soon as possible. Logically I know if I am at 1/2 tread depth, put on an unused spare with full tread depth there could be problems.
Has anyone seen any guidelines on how long you can drive with the full size spare before risking issues because of different tread depths?
Would toyota automatically put the old tire on for use?
Not worth worrying about in my opinion. If these modern AWD systems are all that sensitive to slight circumferential differences wheel to wheel (I doubt it) then I wonder how they cope with the inevitable front-rear difference caused by the heavier front end squishing the tires down more than in rear.
Has anyone out there ever actually seen damage to any differential caused by slightly different tire circumferences?