I thought I would share my experience with installing 16 inch wheels for winter in Canada on my 2024 Kona EV. I found a set of 16" Continental VikingContact 7 tires at a very good price compared to 17" (I paid just over $500CAD all-in instead of $800+ for the 17's). I contacted the dealer to find out if I can downsize, and he said no. I was surprised because the ICE Kona comes with 16" wheels on the base trim. I did some digging to find out that the EV has large calipers in the rear and some 16" wheels don't fit (I didn't find any info on the 2024 MY, only previous model). I looked around for some used rims and found a set of old Hyundai alloys (from and Elantra, maybe?). The garage that was selling them tested the fit and there was a little less that 1/4" clearance around the rear caliper: success! Obviously that's still not a ton of clearance so some 16" wheels might have interference, but worth giving it a shot (16" tires and wheels are cheaper and might even be more efficient).
Your tire diameter is 1.5" shorter. It will make your speedometer read almost 6 percent higher than actual. Not a real big problem but noticeable You also lost 3/4 inch of ground clearance. Again no big deal, but you may scrape a steep ramp you didn't before. Wonder what the difference in weight is.
Right you are. Good observation. The story behind the tire size is that I had originally bought these for a Niro EV that I was in the process of buying but the deal fell through (long story). I decided to keep the tires and try them out on the Kona EV and accept the overall tire diameter difference. A more appropriate tire size for 16 inch on the Kona EV would have been 215/65 R16 (within 1% of OE) instead of the 205/60 R16 I have. I'm not too concerned about the ground clearance, but the speed is something I need to keep in mind. At least my speedometer is reading higher than actual and not the other way around.
