enclosed trailer with 15" tires?

[flash]

I have a 32ft enclosed tag trailer 15" wheels,225/75/15 trailer tires.race car,tools,golf cart,about 9500 lbs.try to buy a american made trailer tire-they don't exist!! want to change to 16" wheels & tires but don't the clearence for it.carry 2 spares,go with E rated tires with max air pressure .change tires every 2 years.light truck tires is a option,but they are taller and side wall support is not what it should be,but some people have gone that way with decent results. good luck.