I?m towing a 18.5? lowe condor, which I think is around 900 lbs. without motor or decking, so I would say less then 2000 pounds total. I have radial ?car? tires on my trailer and they always look flat even tho they have the right pressure. The size is 165x80R13. I saw a set of trailer tires that looked similar in size but the numbers were diff. they were 5.3x12. Will these trailer tires work for my application? Do those numbers mean 5.3 inch tread width x 12 inch rim? If so, I would be losing .1? of tread width and 1? of rim.