I have an 06 crd liberty sport, and my original tire size WAS 225/75r16... I recently purchased new tires and I went with the optinal tire size of 235/70 R16. This actually keeps the same overall size, just wider. In your case, I would not hessitate to put 225/75R16 tires on it, but I would also consider the 235/70R16 as well.. The skinnier 225's will help cut into snow and such, but the wider 235's will give you better overall traction. My jeep is a bit heavier with the diesel, so i went with the wider tires, and haven't looked back. I love the new ride characteristics and feel. I also went with firestone destination at tires, much better than that crappy, good-for-a-year garbage that came on them.