When my 6th gen. Maxima was totaled last winter, I had my winter tires and rims mounted on the car. On my 7th gen. this winter, I plan on using my 6th gen. oem wheels for my winters. Needing new tires, what size of tires would anyone recommend other then 245/45/18?

 

You could do a 225/50/18.
Narrower tires cut through the snow better.

 

Definitely go narrower.

In addition to cutting thru the snow netter, the contact surface has more PSI, which makes for better ice traction.

 

Yes, as mentioned above go narrow. I have the P225's General Altimax Artic's and have them on 17'' 5 spoke alloy rims from Tire rack. They actually look pretty cool because there's almost no gap between the brake rotors and the rims and they barely clear the calipers as well but work excellent in the snow.