I just got a 2012 liberty with 20" wheels , how does 20" wheels
perform on snow and ice ?

I didn't have any issues in snow about 1" above the center caps with mine wearing General Grabbers UHP (which are M+S rated, sizes in signature).

One issue I did have was the backs of the wheels filled up with snow and sometimes when I got above 30mph the steering/back end would judder like crazy. Just had to clear the snow out and it was back to normal though.

ABS handled the ice perfectly bring me to a stop safely and quickly.

So long as you have decent rubber on them it will be fine. :thumbs:

__________________
Marty

"Even though I walk through the valley of the shadow of rice, I will fear no turbo for thou torque art with me. Thy rods and crankshaft, they comfort me."

Depends on the tires, not the rim dimensions