I'm about to switch to my winter wheels and I'm wondering if it would be better to keep one of my summer wheels as a spare instead of the donut. Obviously during the summer I keep one of my winter ones as a spare but if I needed to drive in the snow would I be better off with 3 all seasons and a summer or 3 all seasons and the donut.

 

I would just keep the donut. I don't know about 4th Gens, but a full size spare doesn't fit in the well, and you're supposed to drive extra easy and get it fixed ASAP anyway. Who knows? Maybe your summer tire might have less grip in snow/ice than the donut because of less ground pressure and its now hard and stiff summer type rubber....

JMO

 

Pretty much. The narrow skinny donut exerts more pressure on a smaller area. Summer tire compound does get stiff under cold temps. I was never able to fit a full size spare in my 4th. gen spare tire well.