Stock.

 

On a stock defender the wheel size won’t really matter, tire width and height limitations will remain the same.
‘Something like 33 max height with around 11.5” width on stock offset rim.

Tires actual spec can vary quite a bit, way more than IMO they should be allowed to.
Always best to check the tire of interest factory specs for diameter and section width, tread width too if offered.

 

Rim size is irrelevant

32.6” max diameter before lift/trim

 

Not true. Try a 32.4" O.D. AT tire on a 20x9.5 ET25 wheel and I bet it will rub the plastic wheel well liners before reaching full steering lock. It is also easier to fit a narrow tire vs a wide tire with the same O.D. Case in point would be 265/70R18 vs 285/55R20 where the 20" tire is fractionally shorter but more likely to rub.

 

These examples are related to rim offset coupled with a 30mm increased tire width.

Reduced offset, use of spacers, excessively wide tire will limit you to less than the 32.6" maximum.

Rim diameter has no bearing whatsoever.

 

Sorry for the beginner question, but did your height clearance change when changing to these K02s? I have 20" stock wheels/tires, but I have to park somewhere that I literally have centimeters of clearance as is (coil, no air suspension). I want K02s (can't wait for K03s), but really hope that it doesn't change my clearance.

 

This tire size (275/55 R20 )reduces your ground clearance and height by 0.05" or approximately 1.25mm

ie: non-issue

 

I mean… but maybe. http://11foot8.com