This could be a potential problem with all PHEV owners! I rotate my tires every 10k miles ( I know I should do it at 5k but I'm lazy ) and I have not rotated my tires since I got my Hymotion battery installed. This is what I found today when rotating the tires. The outer edges of my tires are getting pretty much bald but the 3 center tread lines are still at least 3.2mm thick. Actually that are about 3.5mm, 5.2mm, 3.7mm This is a pic of the rear tire. This is a pic of the front tire to compare. The thickness on these are about 4.0mm, 4.2mm, 4.2mm I'm not to concerned about this right now because next year I'm going to get new tires anyway. In the mean time I have inflated my tires opposite of what is recommended. Normally you have 2lbs more in the front. Well I put 2lbs more in the rear to see if that will make a difference. I'm now running 48psi front and 50psi rear. Note: I took the pictures after I rotated the tires since I did not have my camera with my when I rotated them.