Tread on tires

[CygnusSailor]

I was looking at the tread on my 2011 trailer tires. It doesn't seem like the tread is deep like it would be on new car tires. Is this normal?

Thanks,

[hhh]

The thread depth on ST tires is less then auto/truck tires. The tires will go bad due to age before they ever wear out. Personally I would change them now to LT tires, but in no case should you ever let ST tires go more then 5 years before changing them.