I am a "Newbie" Audi owner and I would like to purchase winter tires/rims for my
A4. The tires that are currently on the car are, 225/45ZR17. I have no idea where to begin.

 

You cant go wrong with these:
Nokian Tyres North America
look at their tire selector.
you may also wan to go down a size to better handle potholes without dinging your rims.
I've used the Haka's with & without studs in all my cars, they beat anything else by a country mile. (braking on ice & snow, that is

 

Here r a few links that can help u out,

Toronto car tires & rims for sale - Free Toronto Classifieds at Kijiji

Audi A4 / S4 Winter Wheels & Tires - Toronto Car Parts For Sale - Kijiji Toronto

Audi cars for sale in Barrie, new & used Audi cars - Kijiji Barrie

if this doesnt help reply me onthis post

 

Thank you so much. I will check these out!

 

In Winter you are much better off with 205/55/16 tires. What you want is more pressure per square cm, so a slightly narrower tires reaps big benefits. Also as Frob said the higher sidewalls give better rim protection and more flex to keep the tires on the snow. I installed the top rated winter tire by Tireland - the Dunlop Winter Sports (V rated!) and drive in BC's mountain passes these have been terrific. Good Luck