The last 2 sets of ET streets ( 26 X 10.5 X 15 ) I had have worn out the outer edge of one on the tires all the way to the threads before the line was even worn off the center. Looks like tire pressure may be too low but I run them at 16-18 PSI. First set the drivers side wore like that then this set the passenger side wore like that. The other tire still looks good. Leaf spring 66 nova weighs 3350 lbs. Stick car. Just bought these a few months ago. Have a lot of runs on them. I can understand them wearing out but I have seen cars where these tires look like slicks. If I would run mine that long the outside edges would be worn all the way thru !!! Any ideas ?