My 2011 Outback came with Power Kings, D rated. I had an alignment problem show up the first year. Had that repaired and two new Power Kings to replace the two worn originals. I am below pay load, keep proper inflation, drive 65 and under except the rare occasions I have to pass someone, use the trailer frequently and store it on concrete pads so there is no dry rot problem. The third one blew out on my last trip. I replaced all four with Carlisle Radial Trail RH, E rated, hoping that will solve the problem. We'll see!