ST tires (service trailer) as far as I am concerned, which I learned the hard way, are JUNK. No experience with Toyo ST tires but IF they follow industry standards they are JUNK. The industry tells us that we have to have the trailer tires (ST) because they are constructed stronger. They also say that they will will loose 1/3 rd of their strength in 3 years and should be replaced regardless of the condition of the tread. No other tire looses strength and explodes and scatters rubber all over the highway before the tread is worn down. So I call them Scam Tires. They want you back selling you more tires. If they can sell you ST Tires they know you will be back. After blowing 4 ST tires in 1200 miles I put on some pick up truck tires rated to carry the weight I carry on my trailer including the weight of the trailer. Some may argue the trailer tire is built to withstand the sideways dragging going around turns. Nobody is going to make fast turns with a trailer. Hard cornering when used on a pick up is more strain than on a trailer. These ST tires are a highway hazard. When they fly apart they could cause a a serious accident. I felt that I met my responsibility to the other drivers on the road when I bought my Ram with a Diesel so I could top the hills when towing at the speed limit. I will continue to be concerned about the others on the road by never buying another ST tire. -- email address removed --