http://www.discounttire.com/dtcs/inf...rTireFacts.dos has good info on trailer tire life and maintenance.
I also read on some forum that the sidewalls on trailer tires are designed differently as trailer suspensions are not designed like car suspensions(cars can absorb road loads better). A car tire on a trailer may be harder on the trailer components.
I also read on the same forum that the turning forces on trailer tires, especially on two axle trailers are more than on a car and trailer tires are designed to deal with that issue.
I would always go with a tire that the trailer manufacturer recommends. Robert