Alignment is always advisable with new tires, you want to protect that investment. I'm off to the tire shop this morning. My tires still have a bit over 6/32 inch tread left, but three have had a slow leak around the bead for a year. It's getting worse, especially with the cold weather. They're gonna try to get the rims buffed up and see if I can get another year on them, but I might just splurge on a new set. After a $2k timing belt replacement last year, I'll hold on to this car for a couple more years.