Ok here is the measurements of my tires which haven't been rotated for there entire life of 62k. I also included a pic of my front right tire for tread comparison. These measurements were taken using a 100ft tape measure which was all I could find that would lay flat around the tire however it only has increments of 1/8" so there is a certain "Fudge Factor" involved. These are circumference measurements.
Right Front = 9' 1/4" @36psi
Left Front = 9' 1/4" @36psi
Right Rear = 9' 9/32" @35psi
Left Rear = 9' 1/2" @20psi
Unused spare = 9' 1 3/16"
The left rear is the one that took a nail and has been thought to be fixed :-[
I've pumped them back up to 45psi and will watch the pressure more closely but It will be some time to see if the tire pressure is the reason for the wear descrepency
Right Front = 9' 1/4" @36psi
Left Front = 9' 1/4" @36psi
Right Rear = 9' 9/32" @35psi
Left Rear = 9' 1/2" @20psi
Unused spare = 9' 1 3/16"
The left rear is the one that took a nail and has been thought to be fixed :-[
I've pumped them back up to 45psi and will watch the pressure more closely but It will be some time to see if the tire pressure is the reason for the wear descrepency