Yup, they're definitely 17 inchers. I had new ones put on so I could move 700 miles. I've only put around 1000 on them so far. Primewell PZ900 BL 225/50R17 98W. Low profile ones.
I got the car mainly for it's space rather than it's performance (I needed something on short notice for the move,) and the 17s love to graze my the edges of my quarter panels/wheel wells when I hit some of the sizable potholes we have in the area, especially when I'm carrying much weight in the back. And my struts/shocks are in pretty good shape. I'm not doing a ton of highway miles, so I'm not worried about the mileage change if it goes down slightly, and I figured switching to 15s might save me some weight and negate any loss from changing circumference. Also, they're cheaper to replace. Generally. I think.
Thanks for the advice so far for this noo soob guy. It's much appreciated.
I'll get some pics up as soon as possible with the new tires, but it might be a few days. I go to work and come home when it's dark out, and it will probably spend the weekend in a shop getting some other repairs done to pass inspection...
Until then, here are a couple of tire pics I grabbed off the dealer's site where I bought it. Apologies for the size.