I converted my old classic dominator from 15-in to 16-in. After blowing 22 Goodyear Marathon radials, I had had enough. I just bought some six lug, 16 in rims and then some good 16 in load range e tires. Everything worked out fine until I put a 5,500 lb car in the trailer. It caused enough deflection that the top of the tires cambered in and rubbed on the wheel wells. So I took a hammer and finessed the wheel wells where the rub marks were. Keeping that in mind, I would get the narrowest 16 in tires you can. Something like a 215/85R16. By the way there's nothing wrong with putting a truck tire on the trailer.