Im going through 4 tires per year on my trailer. I have a 8 1/2 by 20 haulmark enclose trailer. I think Im OK on weight. Im carrying a 36" exmark walkbehind, 36" walker, 52" exmark, weedeaters edgers, and some misc stuff. Ive tried different pressures, last year I ran 35lbs and 4 months later on the new tire I started around 40lbs. I cant remember the exact size tire but I know its a 6 ply tire at round $80 a piece. We have alot of cul-de-sacs and the only thing I can up with is the tight turning in them. I guess while turning the tires tend to slide a little. They all dont wear out at the same time. This month the right rear is showing some metal, next month one of the others will be due and by the late fall the right rear will be ready again. Any suggestions or ideas will be apprecieated. Thanks.