At 20000 klm I noticed abnormal Tire wear scrubbing front tires Isusu answer was to rotate tires every 10000 klm I set about checking alignment and found that from unloaded to loaded and with caravan attached the toe- in changed 8 mm. The simple fix was to load utility vehicle and check alignment then add caravan and recheck alignment and by adding 2 sets of paint marks to track rods. I can set to predominantly towing or predominantly not towing in the end these tires did 54000 klm before I replaced them and were worn fairly even.