In fact, trailer tires are designed and manufactured differently than your standard car tires because they're intended to carrier heavier loads, so arguably, they need more care. Yes, there's the "penny method," where you place a penny in the tread to judge the quality of your tires. If the tread doesn't come to the top of President Lincoln's head, then your trailer tires need to be replaced, both for best driving conditions and safety reasons. But there are other factors to keep in mind with trailer tires.
Your Trailer Tires should really be replaced approx. every 3 to 5 years, even if tread level is good. Why? Because the materials trailer tires are built with have a limited life span, which could lead to cracks and breaks. It's better not to take any chances.
Inflation: When you're dealing with the transportation of heavy loads, this is a critical checkpoint. Keep trailer tires inflated to the maximum recommended pressure, as doing otherwise could cause you to blow a tire or the tires to wear unevenly, which could impact your tire quality as well as your fuel economy.
Just because trailer tires aren't on your everyday vehicle doesn't mean they don't need proper care and maintenance, too. Following the above tips can help to maximize tire life.