The "up" part isn't going to happen! 16.5" tires are the heavy-duty tubeless version of 15". For instance, a 7.00/15 tube-type tire will have a same-height equivalent in a 16.5 tubeless with a tapered bead, which requires a special-shape wheel. The overall height of the two tires will be the same, so they could be used interchangeably. Other, similar interchanges would be 10.00/20 and 11-22.5, and 11.00-22 and 12-24.5, I believe. These tires were designed that way to give commercial truckers the ability to run tube-type and tubeless tires on the same axle, without overall height issues.
The only time I've been able to find 16.5" wheels available have been for 8-lug applications, like 3/4 or 1-ton axles. 6-lug 16.5" wheels would probably have to be a special-order item from one of the custom wheel builders.
Jerry
