[ccjohnson]

               
I have attached pics of steer & tag tires we just replaced a while back.  Hoping for some insight as to what causes this. No one at tire shop has had satisfactory explanation so far. I do have a theory!  A bit of history; When we first picked up coach 6 yrs ago we blew a drive tire on the way home.  Fran's brother suggested we get 2 new steer tires for remainder of trip home instead of just one  drive tire. At 10 pm outside of Ozona,TX  all I could get were Bridgestone load range G max inflation 105 psi.  We ran these for 3 1/2 - 4 yrs.  had some "cupping" on steer tires.  The drive & tag tires I put on coach were load range H max 120 psi drive tires.   On the way to Quartzite  1 1/2 yrs ago we again blew a drive tire. We got 8 new load range G max pressure 100 psi (they did not have H available).  My "oilfield" mentality of just run it until it is really broken had kicked in.  After all we had done well with G's on steer axle for 4 yrs.  After 1 1/2 years the "cupping & wear on steer tires was becoming severe.  Tags were wearing a little strange also but not as severe. Drives were wearing perfectly.  I rotated tags & steer tires in hopes of extending life.  Not a great deal of success. after +/- 3K miles driving slow (50-55 mph) on "square" tires, I ordered 4 Yokohama load range H max pressure 120 psi. After +/- 3K miles no strange wear on them and steering/handling has much improved. Running steers at 120 psi.  I pulled up a weght ticket from last time we had weighed coach: 14,400 steer, 20040 drives, tag 8080.  Checked Yokahama web site for recommended load ranges & pressures.  Looks like I have been blessed to not have had extreme failure issues on severely over loaded steer tires all these years. My theory on wear is that extremely overloaded and under-inflated (for the weight) combined with extremely hot roads ( we did a lot of AZ-CA dessert this year) caused the tires to "scrub" on cornering which resulted in strange patterns.    Would appreciate any additional thoughts.
ps: Newell tag on inside: steers 120 psi, drives 100 psi, tags 110 psi.  I will run at these pressure from now on.  Will replace G drives with H in about 1 1/2 yrs.