Replacement Tires

In reading this forum every one seems to say you need to replace the tires after 5 years. It also seems that there aren't many owners that are happy about the quality of trailer tires. On the bigger Trailmanors that take 15 inch tires, has anyone tried light truck tires in the weight carrying range that would be needed? Most older pickup trucks have 15 inch tires, and I was wondering if the quality might be better? If I am able to find a used Trailmanor, probably a 3123, I would like to know if the truck tires are a better option?