Wheel rims for OTK karts?

“Much different” is very subjective. If you are a national level driver on a hot summer day on a rubbered up track, then yes, different wheels will handle differently. If you are a club level racer just looking to pound laps and keep learning, then no. You will not feel much (if any) difference.

If you are curious, start here and read up. There are quite a few topics on this: