They are not functionally identical damnit!
Looks like my RP02's actually weigh closer to 16.5Lb
(Source)
RPF1's in 17X8 weigh 15.6Lb (almost a pound less) and they're half an inch wider.
(Source)
I don't mind opening it up for discussion though. If y'all think that 245/40/17's will be just fine on a 7.5" wide rim. I'll just keep them and rattle can them like Scott's suggesting.