Trailer tire question and help

[Quiky One]

I am borrowing a friends car trailer in two weeks but he does not have a spare tire. I called up the local trailer place and they have the tires in stock. The wheels on the trailer are 15" but I do not know the size of the trailer tire. The tire guy said he has two sizes, 205 and 225. Would it make that big of a difference if I got the wrong size? What size are most car haulers. This is an open trailer.

Thanks Jason

 

[mhogan6]

Prolly ST225-75-15
You can buy the wheel/tire assembly at a trailer equipment store.
Most are Ford bolt pattern.